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Episode 29 - Cutting Board Safety, Wood Dust Allergies, & Cancer Risk (w/ Dr. Seri Robinson)
1.4k Plays5 days ago
Should you cut raw meat on wooden cutting boards? Do the bacteria grow inside the cutting board? Is plastic better? Should you use a finish on wood cutting boards? How often do SERIOUS allergies develop from breathing in wood dust? Should you always wear a mask? What is the risk of cancer for woodworkers? IF YOU'VE BEEN CURIOUS OR CARE ABOUT ANY OF THESE QUESTIONS, YOU SHOULD LISTEN TO THIS EPISODE!
In this episode, we speak with Professor of Wood Anatomy at OSU, Dr. Seri Robinson, about these EXTREMELY important topics. Seri has dedicated years of laboratory research towards addressing these topics and leads a wonderful discussion. A rare occurrence in the maker space where two Ph.D. scientists (Paul & Seri) work together to deconvolute these important topics, cut through fear and misinformation, and come away with real world pragmatic recommendations.
For more reading on these topics, here is a link to Seri's book "Living with Wood: A Guide for Toymakers, Hobbyists, Crafters, and Parents"
and Seri's Patreon all about Wood Safety: http://www.patreon.com/woodsafety
To watch the YOUTUBE VIDEO of this episode and the irreverent & somewhat unpredictable AFTERSHOW, subscribe to our Patreon: http://patreon.com/user?u=91688467
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Transcript
Introduction and Host Backgrounds
00:00:16
Speaker
And we're back. This is Woodworking is Bullshit, a podcast about creativity, art, design, philosophy, and as it were, cutting board safety. I'm your host, Paul Jasper, scientist by day, woodworker by night, and I'm joined with my co-host, Eric Curtis.
00:00:36
Speaker
fine furniture maker and content creator. Are you timeout? Hold on real quick question. Did you because you broke the fucking folding chair last week. Did you bring back the fucking squeaky chair? Did I hear that? That thing squeak you son of a bitch. you This is an audio format Paul.
00:00:53
Speaker
I'm going to try to move as little as possible. And thanks for fucking inter breaking up my introduction. I was doing great. And you you totally side rail now that carry on. Is there any video to this? Could they see you dancing? Oh, yeah. Oh, yeah. there's videos Oh, great. Fantastic. Yeah, those were good dance moves, too.
Guest Introduction and Previous Controversies
00:01:12
Speaker
So you might have heard a voice that is does not belong to one married to Sayi. We have a very special guest today. Our guest is what I would like to call multidisciplinary.
00:01:25
Speaker
Woodturner, sculptor, science fiction author, and last but not certainly least, Professor of Wood Anatomy at Oregon State University, Dr. Sari Robinson. Sari, thank you so much for being on the podcast tonight. Yeah, thanks for inviting me. This should be a lot of fun.
00:01:45
Speaker
Well, so ah maybe I could start with why like why we thought to have you on. So recently you recorded a podcast episode on Shop Talk Live with Ben and Amanda for fun woodworking. And it was an excellent episode. And ah of course i I listened to it, but I i hadn't listened to it. um I hadn't seen it myself, but so many of my friends.
00:02:10
Speaker
had reached out to me because you hit some serious nerves with this. They were reaching out to me to see, they were saying, what do you think of this? Is this true? Can you believe it? I think I was lying. Hilarious. People were so bent out of shape from some of the things you said. I watched the forums. I watched people explode and fly week, seal time. Paul, what were some of the things that people were bent out of shape about?
00:02:38
Speaker
Oh, they are we going to get into that later? We're going to get into it. We're going to get into it. But Kai, they were reaching out to me as their scientist friend to be like, is this true? Do you know her? yeah can Can you validate any of this? No. Is this- Will scientists know each other? learn And I said, small girl, no, actually we didn't know each other. And I said,
00:02:55
Speaker
Like, not only is she telling the truth about these things, of course, but I think we should take it a step further. ah In this episode,
Topics of Cutting Board Safety and Wood Science
00:03:05
Speaker
what we want to do is reiterate the important points you talked about in case anyone didn't see that. But really, the goal of today's conversation is to take the next step.
00:03:14
Speaker
And what that means is more details about it. We wanna also go an additional step about quantification, right? It's not about um it's not about um yes or no black and white. It's really about quantifying the dose and quantifying the risk in some way. And I don't mean like, oh, hazard ratio of 0.25. I mean, we have to put this in terms that people can understand and that's the goal for today. And we also have a question and answer.
00:03:42
Speaker
so I do want to say rarely do you get two scientists who do woodworking and have two PhDs and who love wood as much as me and Saria do. like We love wood and love woodworking. It's the most amazing substance. Rarely do we come together in the same moment to dissect and talk about ah three topics today. Cutting board, safety,
00:04:11
Speaker
ah wood allergy development and cancer risk due to wood dust. So those are going to be the three main topics we're going to talk today. so really huggy Well, yeah they we're going to try to break it up with a lot of profanity and jokes.
00:04:25
Speaker
Yeah, I'm definitely. It is heavy, but I think our audience knows that well, that they get off the rails. Yeah, that Eric is the chaos that it kicks things like.
Wood Science in Legal Contexts
00:04:36
Speaker
So ah sorry, maybe you could start by introducing a little bit about your background, what your lab works on and what your interests are scientifically.
00:04:46
Speaker
Okay, so I'm a professor at Oregon State University. I have an undergraduate degree in woodworking, which is in the art and design field, and a master's and PhD in forest science with specialization in wood science. um I'm a professor of wood anatomy, which means that I do things like wood identification um professionally, so I do a whole bunch of things. but um I end up as like ah expert witness in court cases and I do what I need for like insurance companies and people who are trying to hold it their insurance company to save them money and all that kind of stuff. ah the hallenian question i know that he' du your yeah i's spell I don't want to interrupt you, but you're just going to breeze over like expert witness in court cases. I mean, i did you have specific questions? yeah
00:05:33
Speaker
i I have never been one of those. what and in what In what court case has wood science required? All the time, all the time. Really? So it's so common and not just like, um there so there's so many different ways wood ends up in court, right? It can be as simple. I think the most common is just like,
00:05:58
Speaker
homeowners or builders who have been like lied to about a supplier or something like that and they go to court. and There's a lot of like builders that maybe didn't put a vapor barrier incorrectly and then someone has to come up, um do like a mold and decay because my specialization is how would decay, fungi, interact with wood anatomy um because I work in an ancient art form called a spalting, which is actually what I study. like i' I've also been on the art side of wood. It's just this really old art form of spalting has a lot of applications for modern science and so I end up getting sucked into other things because
00:06:36
Speaker
Um, a lot of people are used to the city of my seat fungi, which are like the traditional wood decay fungi being a problem, but like lots of the quote unquote mold fungi also decay wood. And those are the, like, those soft rotting fungi are my specialty. Like they're my babies. And so if you need someone to deal with like the fungi that turn wood neon pink, that may also be, you know, eating your you know utility poles or whatever, that's me.
00:07:03
Speaker
I do a lot of that. Sometimes and sometimes it's homicide. like ah and it like Sometimes telephone calls fall on people. And then like who's to blame? like Someone was supposed to inspect the pole and didn't inspect the pole, right? And um and sometimes, and this is always like them probably, it's fun, but also kind of sad. It's like,
00:07:23
Speaker
little old ladies who have old houses and want their floor to match or want their deck to match or something like that and they'll get a company and it's always like these they're usually pretty wealthy ah you know I want my I want this like ancient whatever teak floor and I want it to also the new stuff to be teak and then the builders come in they're like okay this is the same thing and then the old lady's like it doesn't even look the same na tea um So we get a lot of those even like pre free-trial type of stuff where she like wants to just like settle it. There are a lot of places that will do with identification on the cheap, like send away type of stuff, but they don't um
00:08:04
Speaker
They don't really do the deep science. So our lab is the, I already tried all the cheap places and I didn't like the answer they gave me. Um, do you want to like be the authority? And so, cause we like, my lab charges a lot, but you get like this thick report with like microscope slides and little, a way too much information, like little arrows that are like, we know it's this, not this wood species, because as you can see here, the sclera form perforation plates are blah, blah, blah. And everyone's just that it's.
00:08:28
Speaker
That's exactly what I was thinking. I was already on that. Yeah. Yeah. Eric, how are you? Sorry. I was working on those during leg day the other day. I didn't mean to to derail. Oh my God. Tell me about what
Wood Safety and Scientific Misconceptions
00:08:43
Speaker
you want to do. That's what I do on this podcast though. so carry on I work with wood and fungus and I have a passion for, or or at maybe not a passion for it, a passion for now, but I get sucked into a lot of what what is dangerous, what is safe, because of the misinformation about fungi in particular and how like terrified people are of fungi and not understanding it's a kingdom and all of that kind of stuff. And so that just kind of cycles into, because people would always be like, you know,
00:09:13
Speaker
Oh, I'm afraid of spalted wood, which is, you know, when fungus is on wood and turns up pretty colors. And I'd be like, no, no, it's not a fungus. You need to be afraid of it's the wood, which then cycles into why should I be afraid of wood? And I'm like, well, let me tell you all the reasons you should be afraid of wood. And then it's just, no, this whole thing. Amazing. Sorry. Okay. So go ahead, Paul.
00:09:33
Speaker
Well, I just want to say to have someone with your background on, ah I guess a mechanism like this or a podcast or anything is super rare, so we appreciate it. um In addition, so I thought I would, yeah I always say I'm a scientist by day, but I never say what I do, but I think maybe now's the time because we'll be talking science today. So my background is I have a PhD in immun know immunology and microbiology. So that is the study of the immune system and the study of bacteria and viruses.
00:10:01
Speaker
um i i did After my PhD and my postdoc, I've been in the scientist the scientific field in pharmaceutical science now for 17 years, and it's still my full-time job. and i i Of course, I still do a lot of immunology. like allergies and autoimmunity, but a lot of cancer risks. So today you'll hear some of this allergy talk, you'll hear some microbiology talk, and you'll you're you'll hear some cancer risk talk. And I think between Sarian and myself, we should be able to at least take a stab at speaking to these things intelligently. Let's hope.
00:10:39
Speaker
So that's who we are. and And that I think it's super rare to have two of us at the same time, which is awesome. I'm so excited. I'm looking forward to this episode for weeks and weeks and weeks. ah So like I said, three topics today, today cutting board safety, wood allergies and wood cancer, dust risks.
00:10:55
Speaker
Now, Eric wanted to start off with a question. Yeah. So, so I mean, listen, Sarah, I've been a professional woodworker for 12, 13 years at this point. And, you know, early on every post that is going to go off the rails on a forum starts. So. Oh, oh, I believe that. Yes. Yes.
00:11:16
Speaker
the the the the The difference is um I understand that your opinion and and research is ah valuable and I'm genuinely curious about what you're going to say um because you're a much smarter person than I am.
00:11:32
Speaker
so ah my What I was going to say was i we all start off making cutting boards, right? like we all It's simple, you glue things up, you put it out for sale when you're trying to sell like your shitty furniture at ah at a furniture show or a craft fair, and you're just hoping that somebody comes by and gives you 30, 40 bucks for a piece of wood because you have bills to pay and you you want to eat at the end of the week.
00:11:58
Speaker
So I have long been on the train of using wooden cutting boards. And a few years ago, I was ah doing a thing down in Atlanta and in was sharing a house with a couple other folks and we had only wood cutting boards in the house. And they asked me specifically ah to make sure that I had a cutting board designated for cutting meat on rather than using the wood cutting boards for the vegetables.
00:12:28
Speaker
And I was the person in the house saying like, no, no, no, there's science behind it that says wood is actually better for cutting meat on than plastic. But because I'm not a smart person with a PhD after my name, they were like, you fucking build shit out of wood, of course you're biased. So why, why is it that I shouldn't be afraid to cut raw meat or vegetables with contamination on a wooden cutting board?
00:12:56
Speaker
All right, so I want to start off by saying that the science I'm about to talk about now is not mine. So you can send your hate mail somewhere else. ah this I am going to talk, however, about the like 20 to 30 years of scientific papers on this that if you go to Google Scholar,
00:13:16
Speaker
which is a different side of Google, and you just put in like cutting a board, wood, and bacteria. You can find them all. Most of them aren't even paywalled. And there has been study after study after study that talks about how there's no problems using Robbie on wood cutting boards. And that's because wood is hygroscopic, right? So it's constantly, and all woodworkers know this, right? You know that when the air is humid, your wood swells, and when the air is dry, your wood can shrink and crack. And if you get wood wet, it can also swell.
00:13:46
Speaker
So what it's doing is it wants to equilibrate. So if you dump a cup of water on the surface of wood, it it dries, quote unquote, dries pretty quick. But what it's doing is the wood is equilibrating the water throughout. So it doesn't want a big wet spot in the center. It's dead. We're going to anthropomorphize it. Stick with me. It doesn't want a big wet spot, right? And so that water distributes evenly throughout the board and study after study after study. Yeah.
00:14:15
Speaker
Sorry, is that capillary action? There's a couple of things going on. Okay, I'm just curious. Go ahead. Yeah, part of it is. And so what happens is, and again, lots of studies have done this, if you, thick meat, raw meat on the cutting board, um you know, and if it's juicy, it's just going to start pulling the, you know, the blood down into or whatever's on it. But the thing is, excuse me, I'm having, I'm having some carbonated beverages right now. And so, you know,
00:14:43
Speaker
an audio pie. That should be really fun. It's safe space. I'm going to, I'm just going to burp. Um, so the idea is, you know, you wash it, but there's bacteria on the surface and the bacteria is in the water. And as the water gets pulled down into the wood, the bacteria syria gets pulled down into the wood and the surface remains perpetually clean. And this is a very fast action. And so this is really how fast, to talk about how fast, like how fast are we talking? Is it minutes, minutes fast?
00:15:14
Speaker
Yes, it's it's well under an hour. um so the it's So in our testing we did with finishes on the unfinished wood, it was it was under a minute. It was just like an instantaneous for a lot of them. And so so that means that it's perpetually cleaning, if it's wet, if it's dry. I mean, if it's dry, it's probably relevant than anyway.
00:15:36
Speaker
um So you can rinse it you don't even need use soap You can and I would say do you so um just because it moves the fats off a lot better But you don't need so because you just need water to pull it down and then you give it time It needs to equal liberate and then you know in 24 to 48 hours, you know You can be sure everything is locked down. It doesn't come back out. There have been studies on that. There have been studies where they cut the cutting boards apart and tried to re-isolate from the center of the bore, but it just dies because without water, it dies.
00:16:08
Speaker
and So is that the thing that, so I know you've said in um the article that you wrote for Findwood working that it's antimicrobial because it gets pulled down into the center and then it dies. But what is the actual mechanism that's killing it? I assume that like, you know, a cutting board being made of dead wood doesn't have an autoimmune desiccation. It's just desiccation. Yeah, it dries off. And even things like, you know,
00:16:35
Speaker
you no food source no you know yeah When we did testing, it was with salmonella and wisteria. Salmonella dies pretty quickly on surfaces regardless. It has to be actively growing in order to function. It's really interesting to look really carefully at the data.
00:16:54
Speaker
this is a very like This is a thing that only really matters so much if you are working with meat or vegetables that might have contamination, right? Like lettuces and things like that that tend to have a higher like E. coli and stuff load. Because salmonella.
00:17:11
Speaker
kind of dies on its own. And so it it's true that like you know if you were just dealing with something with salmonella and you just walked away from your plastic cutting board, if it dried out, chances are the salmonella might not fare so well regardless. So what we're talking about here is a really interesting action that happens that means it helps decrease the cross-contamination issue. So you don't have to freak out about vegetables and meats and moving things around. like Your steak board can be your carrot board.
00:17:39
Speaker
can be your breadboard um because of that quick movement as long as it's wet. And Sarah, you made a good point on the other the other podcast that you said, listen, meat's not the only thing with bacteria on it. Your vegetables have plenty of bacteria on them. So it's um it's sort of a mis it's it's sort of misguided that the meat's dirty and the vegetables are clean necessarily, yeah?
00:17:58
Speaker
I mean, we keep seeing recalls on all these vegetables, right? Constantly for all this different bacteria. and And so I'm like, yeah, so, but yeah, definitely be concerned about the meat on your cutting boards. That's, that's the problem.
00:18:12
Speaker
So it sounds to me like what you said was the imperative part, the important part is that the cutting board has some moisture on it, whether from the material or from just rinsing off rinsey shrilock in the sink in order to allow the the hydroscopic action to pull the bacteria into the center of the board.
00:18:32
Speaker
Yep. Interesting. Okay. And so you dismissed you dispelled one myth that I heard commonly. when i So I would tell people this same message 10 years ago at the furniture Institute when I was teaching a cutting board class, I would tell them this research. And one of the questions was, well, doesn't it get pulled down and then doesn't it proliferate inside the board? And it's like, no, it it dries out desiccates, like you said, and there's no food source for it.
00:18:56
Speaker
and So that's an important myth that I think you busted one thing you said that really I Wanted you to elaborate on is you said washing with soap doesn't really do much and I always think of soap You know as a microbiology immunologist like soap Mechanically disrupts membranes of bacteria, right? It is it is antibacterial by definition So why doesn't soap ah help with this?
00:19:21
Speaker
It's because usually by the time you get around to soaping it, a lot of it's already been pulled out. And so yeah it doesn't hurt anything. It doesn't hurt to use soap. The soap really helped if you got like if you've been working with like ground hamburger or something that's really fatty and there's a fat layer on your board, that's good to do the same thing of finish will, right? Which we'll talk for about a minute. So you want to get that oil layer off. But if you've just been chopping like vegetables or something that's not real oily,
00:19:49
Speaker
The water works so fast that the soap, again, this is not my research, so don't send me hate mail on it. ah But there has been testing about soap versus no soap and there's no statistical difference. So like if soap makes it real better. So when you when you say, when you say no statistical difference, I think what you're referring to, tell me if I'm wrong, what you're referring to is that the number of bacterial colonies that came back up off the surface was not different.
00:20:14
Speaker
Yup, it was just the same okay regardless of soap versus no soap. All right. how about So I was thinking about the pulling of the water and the bacteria with it off the the cutting surface. ah all of us All of us woodworkers tend to think, well, I'm speaking for a lot of us, maybe maybe not all of us, um that end grain, because of its orientation, tends to pull in more fluid faster than, say, face grain or side grain. Is that true and does it matter for the cutting board, do you think?
Cutting Board Material Comparisons
00:20:44
Speaker
Add some paper. It did draw you a picture. Well, you also have to speak it because it's an audio podcast as well. Yes, yes, yes. But also who doesn't want poorly drawn 2D stuff then explain to them. I don't know. That's the best. Yeah.
00:21:00
Speaker
We are you are gonna have to sign it so that we can sell it though. That's that is a rouser You're not gonna get any the only reason I passed illustration in art school ah was because I hurt my hand and Had to use my not dominant hand and they thought that was the reason but I was bad.
00:21:18
Speaker
Sarah, are you going to tell me that the rays make for like side grain that I ever believe in? Yeah, you're going to tell me. Is it really? Yeah, so it really the rays. Well, I mean, I'm going to let Siri expound on this, but ill i'll while she's drawing, I'll just, you know, still the space. You know, we always think of it as a bundle of straws, but that's not exactly accurate with ah perpendicular to the straws. If the straws are running up and down perpendicular to that sideways or other channels and other. Sure. Sure. Sure. As Ray and. All right.
00:21:48
Speaker
And so, go ahead. Behold the art that I have drawn for you. This is wood. It's incredible. For those of you listening on the audio, this looks like nothing. This looks like um some toilet paper tubes stacked on top of each other lengthwise, and then some coffee stirrers going at 90 degrees to the toilet paper tubes. And that's what wood is. It's toilet paper tubes. Hey, they're made out of wood in the end, right?
00:22:17
Speaker
and and then conquerors going the other way. Okay, so here's the deal. Everyone always talks about end grain, right? Because they're thinking, but right, that the highway of wood is mostly up and down and they're not. That's wrong. um It is more true for woods that are ring forests, you in woodworking, they call them open grain, which is a misnomer. and We're not going to use that because we're better than that.
00:22:41
Speaker
ring porous and so the ones that have big early wood and little late wood like oaks and elms and ashes have really big vessels really big toilet paper tubes and they can move stuff really fast but there's lots of woods like maples and beaches where all the toilet paper tubes are tiny and the same size and it just doesn't because not um So, but they're arrays, right? Not all the cells in wood go up and down. A significant portion of them actually move in and out. They move radially. And those conduct very well as well. And in fact, all of these things conduct because here's a fun little edit. um You're going to hear this as I go. Oh, you poke poles through the whole thing. I love you. You just started into a three dimensional drawing. Yeah.
00:23:27
Speaker
There are pits, because things have to diffuse between the cells as well, right? So all of these different cells have holes in them that allow for more conduction throughout. the n are more Yeah, I see. It's far more porous than simply like end grain is the big straws, right?
00:23:45
Speaker
Yep, no, it water moves every possible which way. Now does it move ah ever so slightly faster ah through the end grain on some species? Yes, it does. Not on softwoods, mind you, on hardwoods. um But also no one makes end grain cutting rods as far as I know that are just the wood cookie.
00:24:06
Speaker
ah and They're always glue ups. And so now we start getting into why we don't like finishes on cutting boards and why we don't want to use glue ups because in order for wood to work and be hygroscopic, it has to be able to diffuse moisture. And so what is glue?
00:24:22
Speaker
Glue absorbs into the wood, blocks up all the cells, and holds the wood together. So if you stick glue in your wood, you've just lost part of your highway. It's like filling that highway in with cement. And what are end grain cutting boards? Lots and lots of tiny little end grain pieces glued up. So your board is like 50% glue. And so your highways are just, they're they're not nearly as functional. So any benefit you might have gotten um from that orientation is really not down with the amount of glue you have. Well, at least on the seams, right? Yeah. At least on the seams, right? Like the glue seams themselves are polyvinyl acetate, I assume. So it's like a form of plastic, essentially, right? Yep. And so you put plastic. It's just, yeah, like basically on those seams and however far the glue diffused out from the seam, you've clogged those highways that normally move moisture with essentially plastic.
00:25:19
Speaker
so yeah And you might think, no big deal, right? There's still plenty of wood on there. ah Except, um and this is my research, so you can send me your hate mail on this. ah like So we looked at what what role the finishes play, because everyone who sells cutting boards will try and sell you, upsell you some sort of like conditioner thing that they have. You got to condition your wood. Your wood's got to look hydrated, which is ridiculous. Wet wood molds, you don't want hydrated wood.
00:25:44
Speaker
um You know, you got to keep it shiny because wood's supposed to be shiny, that one I don't get either. Something to put on it that you have to keep putting on it so you'll keep buying it. But all those things do is they clog up your highway. And not only does it prevent you from moving the bacteria with some moisture, um but our study actually found that a lot of those, all the finishes we tested um actually grow more bacteria.
00:26:10
Speaker
So it's staying on the surface where the conditions are good and it's getting air and it's getting moisture because, you know, the board's wet because you did wash it and it's multiplying. And so finishes, linseed oil, mineral oil, all of those things, they actually grow more bacteria than if you just left it alone. And so yeah, that's, that's fun.
00:26:32
Speaker
is Is there any indication as to, say, how many washes it would take to remove that layer? Like, let's say you just put one layer of of mineral oil on or whatever it is. How many uses and washes would it take to remove that layer enough to make it better? I don't know.
00:26:54
Speaker
Yeah, well we haven't studied that. we If you used a non-hardening oil, like a mineral oil, it would probably eventually come off, right? One layer. Linseed oil is a hardening oil, so that's not coming off. So I guess the the reason I'm asking is like the from the practical perspective of people making cutting boards and trying to sell them.
00:27:15
Speaker
We, I just think generally as a society are so used to seeing wood that has that traditional oil-based finish look to it. Then when we see even like a water-based finish, we're like something about that feels flat. It doesn't feel as pretty as a wow factor. Right. um So I think invariably if you're trying to sell, cut if we're, if you're making cutting boards, Hey guys, you heard it. You heard it here. Sari said, don't put any goddamn finish on that board. That's the YJ move. And I'm, I'm a hundred percent for that. But for the folks who are thinking like, Hey, I still have to sell cutting boards and people want to buy cutting boards with finish on it. Like what, it sounds like mineral oil is the way to go. I would, I would say sand better.
00:28:00
Speaker
Nand better. Well, make it shinier through sanding. Not burnish you and just make it, yeah, make it a little nicer looking, right? So, you know, sometimes the month is tight and I need a little extra cash or my kid needs braces or something and I'll make a slab cut me for it or something like that, right? How much did you sell on a cutting board for that that pays for braces? ah That big regime with your, your Oh no. ah Yeah. Uh, my cutting boards aren't cheap. The best part is I make slab boards and so they just don't even, they don't take a lot of work, but I, I tend to work with figured woods and lightly spilt. Like, so they're, they're pretty, but they need to be shiny because people are used to them being shiny, but also right. No one's buying a cutting board for me with a finish on it. Like they know that. But if you later, I sand all my boards to 400 grit and then wet sand them and they're perfectly shiny. Like they glow and that doesn't require a point of oil.
00:28:51
Speaker
Yeah, you could just I think I said this on the fine woodworking podcast It was just that you could just like up your woodworking game a little bit Sure, just be better. Well, you need better. You could be a better woodworker That's true. You also said put a put a finish on that's just not it doesn't stay there very long. It comes off quickly like a wa well that wax Yeah, that's what I was trying. Okay. Well wax is better than mineral oil. Yes in my sanding is better than all of them Okay, so right so, sorry, extrapolating on what you said about the effect of glue joints, like being sort of, you know, interrupting the highway of of absorption and and being a place where, and and finishes being a place where bacteria can just kind of sit on the surface where they're happy with with moisture. How does this explain the FDA's recommendation to move to plastic cutting boards for so long? I i i cannot speak for the FDA. yeah I, a spume,
00:29:45
Speaker
It's just for ease of cleaning because you can put a plastic cutting board in the dishwasher and have it spray the bacteria all over the place, but get it off the cutting board. um But would cutting board take some care?
00:30:00
Speaker
it recall yeah Yeah, I see that. yeah I recall a paper, if I don't remember whose lab it was, that showed that plastic cutting boards that are full of bacteria, if you put them in the dishwasher, the bacteria gets sprayed everywhere, all over the things. Apparently, and they they were able to show that, they were able to isolate some of that, which I thought was hilarious.
00:30:23
Speaker
ah yeah Well, sell so again, with one the trend of mike microplastics too, um ah you know, I've been all over that literature recently and the idea of like cutting plastic up, making little divots that never heal, never go away and are just these little niches for bacteria to grow and you're putting them the in the dishwasher and then you're also consuming even more plastic than you do already involuntarily. It's just plastic cutting boards never made sense to me.
00:30:54
Speaker
It's constant. And with the thing is, though, with wood, you do have to take care of them properly. So if you're like the solid slab is kind of the way the way to go, you know, avoid the glue, all that stuff. But now you have and it can be hard to source a thick board because you don't want some wafer thin thing because it's going to warp on you. Right. And so you want a nice thick piece of wood. And now you've got You have to think about, people are used to like just really beating the crap out of their boards, right? Because they've been laminated up and all of they they've oiled them so people could take care of them like they were plastic. But you can't do that with wood. You guys know your woodworkers, right? It has to have air flow on all four sides to dry. You can't just like wipe it down and put it in a cupboard. It's going to mold. You have to actually treat it as something that isn't plastic or ceramic. And I think that that, in a commercial kitchen, that's a hard thing.
00:31:46
Speaker
that's That's a hard ask. Okay, so ah in a moment of ah truth telling and vulnerability, I will say even though I knew the science of wood ah sucking it in, I do have cutting boards that are glued. And I do think I used to finish on them originally, but that was years ago. So my guess is that's largely gone.
00:32:13
Speaker
um So the question in my mind started to become, well, okay, let's say i did ah they have glue ups. They do, right? They have plenty. They're plaid, actually. So they have a lot of glue lines going in each direction, and they're gorgeous, and I love them, and I'm going to have a hard time stopping to use them. So playing devil's advocate with myself about the bacteria counts, what I want to know, and I don't know if you have this answer or if there's data to even inform this answer,
00:32:44
Speaker
How big of a risk is this? How often does someone get sick from a bacteria off their home cutting board? I don't even know how to test it. I don't know what no data would inform that. yet i Do you know anything about that? How would people even go to that conclusion? It would have to be self-reported. And who's going to say it was my cutting board? and Wouldn't they naturally say I bought bad meat?
00:33:06
Speaker
or yeah like how would they get out? there that's fair There's no way to know about it. Well, see, I haven't had food poisoning in the last ever that I can remember, at least 10 years. so that so and Pushback, sorry, pushback. ah That makes me feel like whatever I'm doing in the kitchen with my cutting board must be okay. I mean, none of us have had food poisoning that I can ever recall.
00:33:31
Speaker
So does that say that the risk is in in a broad sense low? I mean, I know you're speaking from first principles. like you went ah Just a moment, sorry. When people ask sorry questions, sorry is in a tough spot because they're asking her for recommendations. So she's going to go to best prince sorry they're going to go to best principles, right? They're going to say,
00:33:50
Speaker
um you know this is what the science says about bacterial counts and so I'm going to tell you what's best about bacterial counts but what they can't tell you is Well, this is your actual real world risk because it depends on your behaviors, how you treat that board, what you're buying, you and system your immune system, how much bacteria was on it? Did you cross contaminate? How much do you cook your stuff versus not cooking? Because of course cooking kills bacteria. So I feel like series in a very tough and this sorry, this relates to some of the people who were contacting me like angry about your previous answers.
00:34:28
Speaker
I'm like, they're in a ah very tough pickle because you're you're being asked to give advice based on first principle science without risk information at hand. So what do you do? Like, give me a break. I'm telling you what I know. I'm telling you the best answer I know. But how do we assess risk?
00:34:45
Speaker
i I always tell people um it's not my job to tell you what to do in the kitchen. It's my job to give you the tools you need to make your own decision. Like i am I'm not your dad. um I'm your local wood scientist who works for a public university. I have given you this information and you can choose to do with it what you want. You can just ignore it.
00:35:09
Speaker
um What I will say is that when you start thinking about, and I wrote i wrote an article about this, I think for like Oneida blog systems about um consent in in in life, right? in In woodworking in particular, right? like So what you do at your home with your own cutting board is your business.
00:35:28
Speaker
um But if you have people over and let's say one of them's immune compromised and you don't know that one of them's elderly one of them's a young child one of them's something like that maybe um and you cook steak and like you're fine with a little like E. coli because you're a grown adult with no health concerns, but maybe your 98 year old grandma ah You know doesn't have that same immune system and go she's not consenting ah To you know your potential contamination issue. She doesn't know it's not she hasn't consented to bat risk And so what your choice is, you can make those choice for yourself, but I think when you start talking about vulnerable populations, you have to take a step back and think like, you know, how how can I like protect those I love? But also, why why are you fighting? and Is it such a big deal to just not put a finish on your cutting board? Like, yeah is this odd tiny thing where you spend less money?
00:36:27
Speaker
Really? No, I see. But you guys tell grandma over this. and No, I mean, people are going to people are going to get upset about that language, kill grandma, right? Because we just said on one side, we can't quantify the risk. It's just not quantifiable. There's no data. And on the other hand, you're saying,
00:36:44
Speaker
are we going to kill grandma? So I think people are struggle with the two sides of that. scaling You don't know the risk. How can you say it's important about um you know people consenting and kill grandma when you can't quantify the risk? So I think that's why people get upset.
00:37:03
Speaker
is it
00:37:06
Speaker
can we Can we go out on a limb and just say, like, Sari is presenting information and what you do with that information is up to you? And if you have if you take Umbridge with what they're presenting, then don't fucking email them. Like, let's just just like let's just establish that baseline right now, right? Like, it was cool. yeah They don't know the message. I don't think that our listeners would do that, but I just want to put that out there.
00:37:31
Speaker
You could just ignore me, it's really easy. Right, right, that's the thing. just You don't just be like, that's information that I don't feel like i imparting in my day-to-day practice, and that's fun. All right, so from a practical standpoint, Eric, have you ever had food poisoning at home that you can't recall? Not at all. Okay, me neither, and neither has my family. So in terms of risk, that's all I have to go on. So am I going to keep using my glued up cutting boards? Yes, I probably will. Do I believe the research on bacterial counts and the hygroscopic pulling down of bacteria off the surface? Absolutely. And I think the next cutting board I make, maybe I'll do it that way.
00:38:10
Speaker
So yeah everyone has to make this risk, you know benefit cost calculation individually, but that's not Sari's job to do for you. Her job is to present the data right about how wood works and how bacteria move.
00:38:27
Speaker
can Can I ask kind of what might be an asinine question? um But it's very much related to cutting
Wood Countertops and Safety Considerations
00:38:34
Speaker
boards. And I want to ask this question before we move on, because I know a lot of people have like butcher block countertops. I just bought some from my home that I'm going to install, you know, in the next few months. Is there obviously you can't pick up your cutting your your countertop and put it in the sink and wash it off?
00:38:52
Speaker
So so ah how did these principles differ when you're talking about a wooden counter? Because I do know people who are like, yeah, I'll cut shit up on my countertop. Of course I would. just Good question, Eric. how How does that change things when you're talking about a surface you can move to the sink and wash off versus taking a soapy sponge and and wiping its surface down? Well, the the shorter answer is you could just get it wet.
00:39:13
Speaker
um If it's unfinished and move it down, but the longer answer is I get this question a lot it those countertops can't get adequate airflow on all sides um and so I yeah Like i've I've never tested one right I've um I would I
00:39:32
Speaker
I think that's probably gonna be a case where you're just gonna have to use finish because I think you run the risk of your countertop molding potentially with the moisture moving down in and the airflow not happening underneath the cabinet. um But then it also means that your countertop isn't like necessarily being antimicrobial, but like can you could also just wash it. like you right you know right and Maybe don't put the steak directly on the countertop.
00:40:00
Speaker
but so Okay, so don't spit Asia's fish on your countertop. All right, got it. Yeah. All right. All right. So what one more question before we move on to cutting boards and allergies. For those woods that have very large pores, and I'm thinking about like red oak in particular comes to mind.
00:40:17
Speaker
um I've heard you say that they're fine in the past, but the question that always stuck out to me, and I didn't know how to answer it, was, does food particles go into those large pores? And do they does the food rot in those large pores or decompose?
00:40:35
Speaker
I haven't seen any science to suggest that it does. And there was a lot of testing done in a lot of those articles. And so um at this point, I would assume that it probably breaks down and moves down in with the like the washing. Again, I haven't.
00:40:51
Speaker
I'm sure there are papers on it because that should be something that should have come up where someone was like, I, you know, rammed a bunch of bread into it to see what was going on. I have like, i you know, some things are pasty and they, I mean, those like mashing garlic on those. there has Those like or that are big. Those are big. I mean, food can certainly fit in them. It does. I can tell you that garlic and those kind of things, they do move down over time. um It will get sucked down because people often are are concerned about the smells.
00:41:18
Speaker
Or the staining, like if I cut garlic on the board, well, is it gonna smell and if I cut blueberries on it, is it gonna stain and all of that stuff. It takes about two or three days of you wash it and then you let it sit and you are, but it it goes down. So over time.
00:41:31
Speaker
yeah will That was really interesting to me in that article that that you mentioned the staining specifically because like you know i I cook with a lot of different spices like turmeric and curry and things like that, that have that that particular color and stain. and i have not And I've never known why I always assumed I was washing it off the surface like after a week or so that coloring would go away, but it's being drawn into the actual object, into the spoon and the cutting board. That's fascinating.
00:41:58
Speaker
For the fun woodworking article, I just put a bunch of frozen blueberries on a cutting board and I let them feel they stained worse than anything and just stained it. And then like I took a picture of it every day and you know, day seven, it was gone.
00:42:11
Speaker
to file it. I love that. Okay, so the now the next connected issue with cutting boards is and and what comes off them is extractives or parts of the wood that come in contact with your food and then become part of your food and maybe you eat it or maybe it goes in a pod and it dilutes away. It's it's hard to say. It depends on your behaviors and that speaks to something. Actually, sorry, we didn't talk about this but um Maybe we could just stop for a moment and give a caveat. or ah How hard is it to to paint the dangers or or the concerns of wood with broad brushstrokes like we're trying to do? Can you can you speak to the the challenge of that?
00:42:54
Speaker
This is a really good um conversation to have. So the if you go into the literature, it's very it's very specific, and it's very nitpicky, and it's very under this condition, this, and with this condition, this, and this. And then when you need to communicate it to a broad audience, there's something that we call a rounding error that occurs.
00:43:12
Speaker
wherein, you know, if if we're talking about, say, finishes on wood. um Different finishes and different wood species moved bacteria at different rates. um But no one, usually an LA audience, wants me to sit there and go through, all right, so if you put one coat of linseed oil on red oak at this time, this is the bacteria count versus beach, is it this one? Usually when these things happen, we just, we do these broader things where we say,
00:43:38
Speaker
um Overall, every wood species was antibacterial. None of them sucked. And if you go into the literature, then you'll be like, you could see, all right, wow. Well, actually, European beach did it better at this condition, and oak did it better at this condition. so But that's usually, it's so down in the weeds that I lose people. Scientists lose people if we start getting that nitty gritty. And so yeah the idea always with communicating science is to give you enough that you can either say, OK, I'm good.
00:44:09
Speaker
or say that piqued my interest enough, I'm going to go find the paper and I want to read more. But if we land blast you with every iteration of every test we ran, ah your eyes would glaze over. Yeah. So no, any time anyone's communicating science to a lay audience, they are they are rounding.
00:44:28
Speaker
Yes. This sounds to me like when i I'm teaching a class and in, like we all know that wood moves, right? It expands, it contracts. And then people are like, well, how much does wood move?
00:44:42
Speaker
ah it depends It depends on so many different, in fact, the species, the the the cut of the tree, like all of those things. So in cabinetry, the general rule of thumb is a quarter inch per 12th, which is a fine rule. Like it works for 99% of the woods, but half the time you don't need that because that wood's only going to move a sixteenth of an inch because this quarter saw on walnut or something like that.
00:45:05
Speaker
Or you get that one exotic, cause that's a rule for domestics. You get that one exotic that wants to move twice as much as that. And then in five years, that cabinet blows apart and people are pissed at you because they're like, well, you said a quarter per 12.
00:45:19
Speaker
and it's And if you looked that movement up you know in like a wood anatomy textbook, met even just for undergraduates, we have huge tables that it's by species to subspecies. It's radial shrinkage, tangential shrinkage, longitudinal shrinkage, volumetric shrinkage at different moisture concepts. and so And that's just for undergraduates. That's for like 20 year olds.
00:45:40
Speaker
That I have, I have that sheet laminated in my shop. And it's one of those things where like, I reference it because I want to know exactly how much the species is going to move. But again, I've shown that to students and they just go, I'm just going to go quarter by 12. I get too much. Yeah. no yeah yeah Well, the quickest way to lose someone when you're trying to communicate information is to give them too much. Okay.
00:46:04
Speaker
bullet we're not gonna do that. But ah no, but i do I do feel like, sorry, you're in a tough position often, being the communicator of science. And I know that because I'm in that position very often as well. Especially- Yeah, how did COVID go for you, buddy? Yeah, yeah. COVID, as an immunologist, I had people contacting me left, right, and center about vaccine and risk. We're not gonna talk about that, but Let it be known it was a lot dealing with them. We should compare emails sometimes I bet be I we could have a drinking to sit in that conversation keywords Keyword number one. Fuck you. Okay. Um, so ah Sorry, well, you gave or do you get so called scientists? I get that one in like every email I Didn't know no. I I well, I haven't had that that that's awesome. I We're actually we're actually thinking about talking about how woodworkers react to this kind of information later in the show or in the in the Aftershow because sorry has some tasteful. Yeah, I want to hear those bangers so that
00:47:15
Speaker
Yeah, yeah, yeah. Okay, so moving on to allergies. So, sorry, what, you know, the exposure to an allergy from a woodworker usually takes place in the form of, I'm not that careful in the shop, I don't have great tusks collection, I don't wear a mask, and I've noticed that my nose is starting to itch when I cut black walnut, or now I'm actually fallen allergic.
00:47:42
Speaker
um Can you kind of set the stage about wood and allergies for people who just don't know anything about it?
Wood Allergies and Extractives
00:47:49
Speaker
Um, so just as a really broad discussion, so wood, if you, if you stripped like everything out of wood that makes wood unique and just took it down to its base components, all wood would be the same color and the same weight and the same everything. So what differentiates different species and things about autism genetics, obviously, is going to be its extractives. And so that stuff that the wood makes to protect itself.
00:48:16
Speaker
um And we could go into all the science of it, but all you really need to know is if a wood has a smell, if it has a color, if it has a weird texture, like it's oily or it's sandy or something, but that's all stuff the tree has made. Those are extractives. And they're there to protect it from things in the bacteria kingdom, the animal kingdom, and all of those kinds of things.
00:48:35
Speaker
And so things that are in the animal kingdom include you, but it also includes insects. And so you may think like, what do I have in common with like a wood boring beetle? That's ridiculous. Well, ah more than you might think. And so you actually have to, I mean, it's true.
00:48:52
Speaker
ah Yeah, so you have to think about if the trees making these things to be toxic, right? Obviously, they're not going to kill you. Like what kills a beetle doesn't kill you, hopefully. um But it does have an effect on you.
00:49:10
Speaker
um And that tech um that effect may be allergy. It may be toxic in a different way. There's all different ways um They affect you and I know that people have a really hard time conceptualizing this But it's interesting because I find that people don't have as hard a time conceptualizing it when we talk about animals So, everyone, I think, knows that you can't put horses on black walnut. Like, black walnut shavings are a big problem for horses. Horses are giant mammals. Like, like that's just like contextualized that. It's black walnut can take out a horse. Now, again, they're not us, but it's it's a good reason to be at least cautious, to ask questions.
00:49:49
Speaker
yeah ah to even know, like, cause we just assume mistakenly that wood is a natural substance and it's safe in every way, shape, and form. Never have to worry about wood. That's the safe way to go. But what you're saying is it's not quite, I mean, yes, it's in a broad sense, it tends to be safe for most people, but it's not unequivocally safe because each wood of what, I don't know, 10,000 species has different compounds in it.
00:50:15
Speaker
Right. Yep. So can you start by giving us an idea of what are some low risk, medium risk and high risk woods that you know off the top of your hand? Could you categorize a few common things for us?
00:50:28
Speaker
Low risk woods are gonna be white woods with no odor um and like medium to low densities. Aspen, cottonwood, maple, um birch, beech, things like that. Oaks, a lot of sap woods of a lot of species kind of regardless are pretty safe because sapwood isn't where the extractive are. Heartwood is darker than sapwood most of the time because of the extra extractives, right?
00:50:53
Speaker
um medium yeah It's hard to do the medium versus the hard. like There aren't that many trees that will just flat out kill you. like Not everything is camphor. Tell us about camphor. Tell us.
00:51:08
Speaker
Well, so there are a whole different class of woods that are either very fast sensitizers or can actually kill you. And so I've made lists before in different magazines and in books about like, you know, there are some that, you know, the extractives affect like sperm motility or that, you know, there are there's lots of different things that those, yeah, everyone pays attention to that. and You start talking about sperm motility and everyone's like, what wood is that? Stay away from that one.
00:51:38
Speaker
But you have to be careful of, anything with a smell is usually not great for humans. So you have to be really careful. Things like campers, cedars. and Bloodwood bloodwood sell smells so good. Oh, like us ah my nose in by the sock, because I love this. A lot of people think gasoline smells really good too. and we all I am a smug-nosed people, so I will die on that hill. um kit So when we're when we're talking about risk,
00:52:07
Speaker
ah I assume we're talking about the risk of exposure when cutting it, turning it into dust, inhaling it, etc., correct? Okay, some way releasing extractives, however, that may happen. And so that can happen, you know, woodworking shop, sanding, cutting, milling, it can happen and with exposure. Under educated among us, can you explain to me exactly what you mean by extractive? Like I understand that you said that it's the thing that creates the smell, the color, etc, etc. But what is like, what is that compound that I should be worried about? he's it It's a compound. There's so many different kinds. There's billions kinds. So I can't just be like, it's a flavonoid. It's a silicon. There are so many kinds. It's an extractive. They call it extractives because it can be extracted.
00:52:54
Speaker
Right, so it's not bound to their wood. That's fair. That's the important thing it can move um With the air some some of them move with air the any of the aromatics move with air exposure It can move with water. It can move with ethanol. So alcohols things like that It's just they're all there's lots of different ones and some of them don't move in water and some of them move with air and some of them move with different kinds of alcohols and some of them moves better under heat and So there's there's no real way to classify them other than that. They cannot come out and so like The reader, and the reason that you make cedar chests, right, and the cedars on the inside, um, is that, so you can keep that smell concentrated and then the cedar smell kills moths and things, which are insects, which are in the animal kingdom, which you also are. Um, yeah. And, uh, but you don't put them on the outside. Why? Well, because eventually the smell will go away because aromatic extractives are carried by the air. So unless you resanded it, and right, you wouldn't get any more out from
00:53:51
Speaker
It's, if you're cutting things, you know, you get those extractives in the air, you get them on your skin when you're cutting, but you can, you can wash them off. So like things like black walnut, maybe an issue with a woodworker, but a black walnut table is irrelevant, right? There's going to be a finish on it. No, it's going to be licking it versus. I got nieces and nephews. I don't, you know, get in there.
00:54:13
Speaker
you know You use a cooking spoon and and then you know you put it in a pot of pasta water that's hot boiling water and it's just hollowing those extractives right out into the water and then the pasta absorbs the water.
00:54:27
Speaker
and Well, at least the water is soluble. at least the water soluble like the water solu right um yeah so Some are water soluble and some are not. So so that's that's an interesting example. is Is that a type of thing that lessens with time? like is there like If you carve a walnut spoon, is there X amount of extractives in there and then by the hundredth use, like you're not pulling any more extractives out?
00:54:51
Speaker
There are a limited number of extractives, but it's not just going to be on the surface because what is hygroscopic as we've talked about where we're going to constantly be equilibrating and then pulling to the. because it happens at the surface, so it'll keep pulling him up. But yeah, eventually, he's got one. bo right It has to be over time, right? Every time you dip that spoon, the water doesn't turn brown, right? Eventually, the brown goes away. And so I guess if you've liberated all the water-soluble extractives, you can from that spoon. And in that in I guess in that condition, would you consider it and inert from an extractive's point of view, at least without liberating new wood?
00:55:26
Speaker
If you got them all out, yeah. So yeah, if you got some great grandma's spoon. So this is great because I have a Peruvian black walnut stirring spoon that I've got pasta and all kinds of stuff. Damage is dodge, move. It's like I've got a Kokobono spoon that I eat every day with. So here's i say of a piece of camphor before I go to bed.
00:55:50
Speaker
Loy helps me sleep before he came on the pod, before he came on. He just did a line of camphor real quick. No, it was the lines of bloodwood right before he came on. So so we we we talk about risk and the damage is done, right? What damage are we talking about? So we're going to take the the safety component in two phases. The first is, do you have an allergy to it?
00:56:10
Speaker
Okay. And the second phase is there are other sorts of talks overt talk. That's so allergy is your immune system reacting to in terms of an allergic response. Then there's just overt toxicity that is not necessarily involving the immune system and or cancer. Right. So that's a different sort of chapter on on with safety. So so many options.
00:56:30
Speaker
Yeah, so first let's take the allergy issue because I think that's something that's far more common and a lot of woodworkers experience. How common is wood allergy? Do you have a rough percent of a hundred woodworkers? Roughly what percent do you think will develop a wood allergy? Do you have any idea? All of them if given enough exposure.
00:56:54
Speaker
so bit like in yeah but Sure, I mean, that's like cancer. If anyone lives long enough, 100% of us will get cancer. But in in terms of like, okay, if you just take a swath of woodworkers out there and you test them with a skin prick test, what percent show ah allergies?
00:57:13
Speaker
I don't think we can make that generalization though, right? Because I had allergies explained to me once as everyone's born with a cup inside them. And some people are born with really tiny cups and some people are born with really big cups and you have a different cup for every potential thing you could be exposed to. And so if you're born with a tiny cup, maybe one exposure is all it takes to become allergic to something. And if you're born with a really big cup, nifty exposures is what it takes to become allergic to something. And we know that all woods are sensitizers.
00:57:43
Speaker
um But you're so much less likely to get sensitized to something like maple because right its extractives are there's so few that it would take so much more exposure versus something like ah Eastern red cedar, which is so filled with extractives that it takes far fewer exposures You get Sun's nice to it yeah so it's So it's a matter of what wood you're using, how many extractives are in it, your personal genetics, whether you tend to be sensitized to allergens, and then exposure, how much have you seen it, right? I did see a study where they just took a swath of woodworkers, and I don't know if this is generalizable,
00:58:25
Speaker
But the the percent of those woodworkers, who and they gave them a test to the the species they were working with, I think it was mostly softwood woodworkers, but they gave them skin prick tests to see what they were if they were allergic to common woods. And it was like anywhere between 2 and 15% of them were showing up with an allergy, just like off the cuff, take a group, no test.
00:58:46
Speaker
ah you know I'd say, ah yeah I don't know if 5%, 10% of people who have wood allergies. Now, I've noticed for myself, and I think, sir, you're the opposite. um I don't have allergies to pollen. I don't have any allergies. And I've only seen very, very mild sensitivity to black walnut dust a little bit. It just is a tickle. And I've got to be really bad to notice it. Whereas, sorry, you're allergic to every wood dust. Is that right?
00:59:16
Speaker
um I have asthma so every particulate bothers me but I sensitize very easily and so it usually only takes three or four exposures for me of anything with a high extractive compound for me to start breaking out hives and to start like having problems breathing and that's I it's not actually that uncommon so every I teach woodworking at the university and woodturning woodworking we don't like many shops we do not allow tropicals in our spaces because you know, they can get in that that dust is forever. So what I do is there's I have one class where we have two weeks of tropical woods work because I figure it's better. It's got to be like drinking, right? If you let them like experiment with supervision, they're less likely to sneak out and turn tropical woods behind my back. And it's a real issue because I I've had to EpiPen myself from people having tropical woods.
01:00:10
Speaker
our way, really? Yeah. And so what we do is we pick two weeks and everyone has to go on antihistamines. It's mandatory. um And they come in and they work with them for two weeks. And so I would say usually a quarter of the students by the end of those two weeks are already showing signs of developing an issue and it can be anything from whole body hives to a lot of eye infections like pink eye, eye puffiness,
01:00:40
Speaker
um concentrated rashes. I mean, I make them we we take all the precautions, right? So I tell them I end class early, we use HEPA vacuums to clean up. And then I tell them you need to go and we're wearing like full face shields, like masks I wear. And I tell them we're ending early, you are to go to the bathroom and you are to wash all your exposed skin and get everything off of it because you don't know what's and I'm not going to be the person responsible for sensitizing you. And in the end, it's still
01:01:10
Speaker
Well, a quarter, like ah twelve that's 25%. That is a sizable percentage. Well, I mean, right week because if non-exotics are 2, 5, 10%, it doesn't surprise me at all that exotics could be significantly higher inducers of allergy. It's also the the context of being in a turning shop, right? Versus like in a wood shop in a furniture shop, if I take it to the table saw and I rip an edge, you know that's that I'm kicking up a certain amount of dust. If I turn a blank of Coca-Bolo, I'm just bathing in this shit. So that's that's not surprising. Yeah, good point. Yeah.
01:01:46
Speaker
um um So, ah and ah just a note about, as an immunologist, I feel like just for a moment, you know, we'll talk about Sari's analogy that started this conversation with some people have a little cup and some people have a big cup. That was that was a really good, helpful visual, actually. yeah so that it really So the question is, why do why did i why do I not get allergies and why does the next person do develop a sensitivity? And the answer of course assuming equal exposure, ah you could always say, oh, different exposure. But let's assume that two people with equal exposure to the same thing, one gets allergies to the wood and one doesn't. Why? How can I explain that? There's two parts of your immune system that vary greatly person to person.
01:02:30
Speaker
The first part is presenting the allergen. like your Your immune system has to present things, ah the cells have to present things to your immune system. And what I mean by present is they have to grab it and like hold it and like show it to your immune system. That's called antigen presentation.
01:02:46
Speaker
that varies so much person to person which part of the wood can be grabbed by your little cells and shown to the immune system the hands are different people to people so like one person might show this antigen to their immune system the next person can't show that same ah antigen what i mean by that is like molecular shape ah the next person can't do that because they they just don't have that that particular ability to present that same shape and so that is the first difference. And the second difference is, do you have the same immune cells that react to those shapes? So I'm talking about B and T cells for those of you who care. And so our B and T cells are very different person to person, and there's a random process to to produce them.
01:03:32
Speaker
So that that's also highly variable. So the ability to show the extractive or the thing you're allergic to, the ability to show it varies, and the ability to sense it is highly random and highly variable with genetics. So that explains like everything of why like one person will react and the other person will not.
01:03:52
Speaker
So that being the case, how then like say I'm a person, like I've been working with Walnut forever and I've never had any kind of reaction to it. Yep. um Are you going to formulate? If I don't have the thing that holds the proper shape nor the immune system that senses it, and yet we also know that given enough time and exposure, I will also develop an allergy. How does that work? It depends. It depends is the answer. You may stay unreactive your whole life because the cells needed to sense it never come. Never come.
01:04:29
Speaker
But your immune system makes cells every day. Every day of your life, millions of new immune cells are born. And millions of immune cells die. So your immune cells and your immune system's in flux. And so your immune system today is different than your immune system 10 years from now. This is sounding like a Russian roulette. Aye. So they're all in the dice, Boil.
01:04:52
Speaker
Do you know anyone who was not allergic to something and then they became allergic to it and then it went away again? Yeah, I know. Because your immune system is constantly in flux. So Eric, ah you know for you and me, we don't have big allergies to walnut. We probably won't, but that's not guaranteed. It's possible they could develop. It just it it just depends because it's a stochastic random process. you can't There's no telling people the exact answer.
01:05:20
Speaker
Stochastic might be my favorite word I've heard. Okay. The best thing is I love it. I love it. Like it really doesn't matter. Like i I'm allergic to everything. If it's in the air, my body hates it, but I can put on a respirator and be a perfectly functional woodworker without any issues.
01:05:41
Speaker
so So that's a good thing to bring up because like we're talking about a lot of scary shit, right? We're talking about allergies, we're talking about, ah to E. coli, we're talking about developing allergies well into the future. And I think the majority of people listening to this podcast intend to work with wood in some capacity for the rest of their lives. There's a ah ah large variety of creative folk who listen, but I think the majority of them are woodworkers.
01:06:07
Speaker
So, i I think it's good to acknowledge, number one, there's a workaround. likes you can You can figure out a way to work safely, that's important. But how, like this is I'm sure this is unquantifiable, but like how worried do I actually have to be about developing a wood allergy or getting cancer from wood dust over a period of like, I'm 37. I'm going to be working. I'm reasonably confident I'm going to hit at least 92 because of my family genetics. So, you know, I've, I've got whatever that math is leftover. Like how scared do I need to be that I'm in the shop five to six days a week making things out of wood? Well, I i can speak to the cancer risk and we'll go to there next, but in terms of the allergy risk, I don't know, sir, you want to offer an opinion first?
01:06:55
Speaker
I just mitigate your exposure, put something on your face and you'll be fine. So I have a different approach. eric I don't disagree with that. I have a different approach. I i keep doing it. And ah if I start noticing some sensitivity, then I'll like be super careful about that particular wood. That's kind of mild, but like I was, i how does a ah on face respirator or overhead respirator versus really good dust collection? How does that change things?
01:07:25
Speaker
It's a tough question. The science I've seen, even like point of, point of generation, dust collection is the best, right? You want something hooked up to your tool, if at all possible, but it's never a hundred percent. And the stuff it's short missing is the stuff that hangs in the air for days. i after The stuff that messes you up. And so you want to have something on your face too.
01:07:49
Speaker
so for So when you say hangs in the air, sorry, I guess you mean those super small particles that weigh so little that they just kind of, yeah. So i I have a garage shop. So nine months out of the year, I have the doors open. So I know like all that fine stuff is gone for me almost all the time. In the winter, I still do open the doors every now and then. I guess you could mitigate that with ah some sort of really good HEPA dust collection system, I suppose.
01:08:15
Speaker
If allergies are a problem, if you don't have any semblance of allergies and you're not that worried about it and you tend not to have allergies, knock yourself out. But maybe if you see that it's starting, maybe you could be like, ooh, I better wear a respirator when I do black walnut. or You know what I mean? and Can I just make one funny observation before we move on? I i enjoy it quite a bit when people talk about um dust control and dust safety and they're very conscious about always wearing a mask and they're they're machining things. And then as soon as they turn the machine off, they taste the mask off, which it like even my idiot ignorant brain is like, but the dangerous shit is in the air for the next 10 minutes. And that's the stuff you're breathing up. It's in the shot for like the next three days, if you don't. Really? Yes, yeah. Wow. Takes three days for it to settle. Very good. All right. Sorry, another question about allergies. And I thought about this from from you know an a immunologist's point of view. So typically with with pollen allergies, people love to get allergy shots. And the idea behind allergy shots is if i experience if I expose my immune system often enough to really small levels of the allergen,
01:09:25
Speaker
what happens is the immune system sees it all the time. It's just the allergens there all the time, every day, all day. And the immune system starts to ignore it. It starts to think like, oh, this is just the wallpaper. I probably don't have to react to this anymore. And you build up immunotolerance. That's how immune, that's how allergy shots work. They're giving you what you're allergic to in tiny amounts over a really long period of time to stimulate tolerance to it. I'm on my third year.
01:09:52
Speaker
I know them well. That's awesome. And my my wife induced tolerance to her pollen allergies through running. She started running every day and just by sucking in all that air every day, she has cured her allergies. I i kid you not. And I'm like, this has to be a immune or tolerance. Can that work for woodworkers who build up an allergy to, let's say, black walnut or something like that? I don't know. um I can tell you that they don't have any shots for it because I've asked.
01:10:22
Speaker
So, but in theory it's your work, right? I mean, not that you might kill your side. So when I was about to say, are you serious? I don't think somebody just like does a line of black. No, and no, no, no. The dose has to be so carefully controlled or you go into anaphylonic shock and die. So don't try it. It has to be a minuscule trace amount and it has to be tested. So don't try.
01:10:46
Speaker
That's what I was going to say. As someone who, again, is allergic to everything, um so like a amount like the
01:10:55
Speaker
I don't even think they were... you It's just water. like At web one point, they were like, we're not even sure. They had to dilute my first dose down so low. I failed allergy shots twice before they were able to do them on me because technology had to get to a place where they could dilute it down low enough that my body wouldn't react to it.
01:11:11
Speaker
So twice I failed them and and I remember them going the second time I failed that they were like We are pretty certain. We just just put saline in you and you still Add it to be epi'd and I was like, I don't know that saline probably came across a piece of grass at some point and Like kissed it and that's what you put in me All right. All right. So let's summarize this area You want to summarize your view on allergies and and wood for us? It sort of closed this chapter on allergies Uh, I think if you're, if you protect yourself when you're in the shop, you shouldn't even develop them. And that would, from someone who has terrible allergies, um, I come at this as a, I don't want to develop anymore. And so I'm not playing that game. I wear a mask every time I'm in my shop and I, when I'm done with my woodworking for the day or the hour, whatever, I take a shower and it's going to allow me to keep woodworking for the rest of my lives.
01:12:10
Speaker
So the more you protect yourself, the less exposure you have, the less you have to deal with it.
01:12:17
Speaker
um Okay, great. um well One last piece before we move on to to our next segment, which, and Eric, you asked this, is cancer development.
Cancer Risks from Wood Dust and Bacon
01:12:29
Speaker
What do we know about cancer development? So I yeah i spent quite a bit of time, I did a deep dive on cancer development with wood dust today.
01:12:38
Speaker
and hours. like I think I was reading for five or six hours today trying to drill down to to some sort of answer about this. and sorry Please you know chime in with everything. so First of all, how likely are you to get cancer from wood dust?
01:12:56
Speaker
Okay, so I want to start by saying the IARC, or the International Agency for a Research on Cancer, classifies wood dust as a group 1 carcinogen. Okay, period. What that means is that it's known to cause human cancer.
01:13:11
Speaker
Okay, so there must be some data out there. you know that That's the starting point. And it turns out, if you look at all the different types of cancer, it turns out that the best data or the most convincing data about wood dust and cancer is nasal and sinus cancers, in particular adenocarcinoma. So that's like an adrenal cell in your nasal passage and your' in your sinus.
01:13:34
Speaker
ah It turns out that is far more likely and the data is far more robust about that than lung cancer. Lung cancer is a very low association. boom So Eric, what if I told you your risk of getting nasal cancer is as high as maybe 50 times higher, 50, than someone not woodworking? How does it make you feel? ah Very simply.
01:14:06
Speaker
I don't think there is anything that I could choose to do in my life that I would enjoy more than making things out of wood, so that is a risk I'm willing to take. Whatever. Like bacon? I would rather- I would rather- You know what? It's exactly like bacon. i I would rather eat bacon and make shit out of oil for 70 good years than live 100 miserable years. You guys are gonna love this. I have data on bacon. I do.
01:14:33
Speaker
I do. Be sure for this episode. i I have data on bacon. I do. So that sounds scary. What I want to point out is 50 times higher or 45 times higher. ah That sounds scary. In fact, it's dose dependent. Like a low exposure woodworker is three times higher, nasopharyngeal adenocarcinoma. Mid exposure is like eight times higher. High exposure is anywhere from cycloten. But what's the baseline? Thank you.
01:14:57
Speaker
Thank you. Thank you for saying that. I well i don't have a PhD, but I'm not an idiot. Okay. ah So this, thank you for asking that because what we're talking about is relative risk versus absolute risk. What I told you was your relative risk. You're 50 times more likely than some than a control that's relative. But what's your absolute risk?
01:15:16
Speaker
Well, I looked that up too. What's the occurrence, what's the incidence of adenocarcinoma in your sinuses? um never even heard one It's one person in every two million people. I feel pretty good about being one people in a hundred million or whatever the fuck it is then.
01:15:37
Speaker
So even if you assume a high, i'm a that they found among high exposure woodworkers over long periods of time, let's say they had a 16x risk, 16 fold risk. That means if you do the math, which I did, that comes out to one person out of 120,000 when you multiply the relative risk times the absolute numbers. So the conclusion,
01:16:06
Speaker
from that kind of study or that kind of data is that number one, what dust is a carcinogen? The cancer sugar is reproducible statistically. It is statistically robust. yeah There's no denying it a hundred percent. It does cause adenocarcinoma, but at what rate?
01:16:24
Speaker
It, it's sort of vanishingly small. Your risk is say one out of 120, like out of 120,000 people who did high dust woodworking, one might have adenocarcinoma. There are a lot of things and or people who are more likely to kill me. So let's talk about bacon. So I saw that I was sitting like, Oh, what's the risk of bacon? I mean, who doesn't want to know their risk for bacon?
01:16:52
Speaker
Okay, well, two strips of- I want to be really clear. It doesn't matter what you tell me right now. I'm not gonna stop baking. Okay. If you have two strips of bacon every day daily, it sounds like Yale. If you have two strips of bacon every day, it adds an 18% relative risk of colon cancer. That's why um bacon is considered a class one carcinogen.
01:17:21
Speaker
But now think about what you said, Eric. How many people get colon cancer? So if you look up colon cancer in your lifetime, what is the out of a hundred people in their entire life? Let's say 80 years on average or 85 years or 97 for you, Eric.
01:17:36
Speaker
um therere ah it's for It's four people. It's 4.4%. So four people that out of a hundred in their entire life will get some form of colon cancer. Now, is it pre say I'm going to add 18% to that. Well, that's 5.2 from 4.4 to 5.2. So out of a hundred people You take two groups. I have a hundred people who don't eat bacon at all and they have no fun in their life. And I have a hundred people who eat bacon every day. The difference in colon cancer is the the group who didn't like bacon was 4.4 got colon cancer in their life. And the group that did eat bacon every day was 5.2. And you tell me- Eat the bacon. Yes. It's like goddamn bacon. Make the thing out of walnut and eat the goddamn bacon. Because people don't talk about absolute risk, it's a failure of the scientific communication.
Wood Safety in Toys and Sociocultural Influences
01:18:31
Speaker
you know it is our second headline with a big but it na know so Concluding about, I also have smoking and and alcohol, but we'll skip that for now. Maybe we can cover it in the after to show if you're curious. but anyway um The point is, you know, adenocarcinoma has been shown for woodworking. The rates are vanishingly low. Most of it was in Europe. And um the U.S., they they did the same data from North America. They couldn't find any association. So, and then you're like, why was the U.S. like already doing better with dust extraction? So, you know, when that's the data, that's the data I found. And there's a lot, I have all the references if anyone wants them.
01:19:09
Speaker
You know, I don't think you have to be worrying yourself sick that you're going to get cancer. I mean, someone will because it's robust and it's statistically significant, but we're talking vanishingly low probability. So please, you know, don't make yourself sick over it. We also, we have the, the negativity bias, you know, like we all will know the one person who developed a severe walnut allergy and went anaphylactic shock or got cancer from there, even in the blood dust. And that's the thing where we internalized and therefore.
01:19:40
Speaker
And therefore we assume that woodworking is dangerous and like that's fine if you want to if you want to wrap yourself and bubble wrap and and Live that life for the next 50 years by all means but you know there Sounds like the three of us are gonna eat bacon and make shout out of wood, please. Please do it. Yeah, sorry, please so i i i' Most of my outreach work is less with wood workers, like what you use in the shop, because there's so many mitigations. You could just put a mask on, get some dust collection, like whatever. What I always want to talk to you about, especially in terms of extractives, is just thinking about um bodies. especially my my I really came into this because I had a kid and I started buying wood toys, and I was appalled by the number of like teething rings and stuff that I saw out of like Purple Heart and stuff like that. and so
01:20:25
Speaker
You just have to keep in mind that what won't have any effect more than likely in a grown adult is very different than what can affect a two-month-old baby. good And so you have, that's why there's all those extra protections for children's toys to begin with. And they don't regulate wood at all, unless it has a finish on it. And so if you're trying to be like, you know, the best uncle ever, and you want to make a teether, and then you're like, Oh, but I know science. And so I want it to be antibacterial. So I'm not going to put a finish on it. So the babies like spit, you know, it doesn't grow any bacteria, but then you make it and they're like, I don't know what he dies on it. So I'm going to use a naturally colored wood. So I'm going to make it out of like, purple heart and bloodwood and coke bolo.
01:21:05
Speaker
And then it's being needed. It's like being abraded in a hot, wet environment. You just have to think about babies so little and like no ability to fight and deal with anything. So you just have to like, it's true that like you can mitigate exposure so much, but there's, you got to think about where, you know, who's going to be using it. Yeah, yeah, yeah. I guess my, my only question that is, is that because kids these days are too soft or,
01:21:33
Speaker
If you want them weed out the weak, that, you know, if you have my grandkids, then you know what to do with. That's, so yeah. All right, so, Sarai, my last question before we switch it up over to Eric for some WTB trivia. Are woodworkers in general open to the science of wood? What's your what's your experience? I would say... um I think this is a complex question, honestly. i
01:22:04
Speaker
I think that it depends who's telling them the science um because I get far less pushback now that I'm older, now that there's gray in my hair. I'm clearly more professory ah than I was previously.
01:22:27
Speaker
um And I will tell you that the, I think in general, yes. Like I would say like 85% probably yes across the board. um If people just see my name in print and don't read anything about me, the comments tend to be, if they are not open to it, they're a lot less scathing if they think I'm a man. So, um and that's really interesting to watch in forums to watch how those pronouns track.
01:22:57
Speaker
Um, and so, and I've had male colleagues of mine deliver the same information and watch that people nod, nod and agree. Um, and so, and then the versus me presenting it, which doesn't happen as much. I would say in the past seven or eight years, when I've got a lot of gray now at the temples, I haven't had that same. So I'm not even sure if it's sexism. I think it might just be ageism.
01:23:20
Speaker
more than anything like you have to have a certain amount of that's true age authority. ah say if to cross I will tell you that when I first started talking to woodworkers about science and wood I was I want to say like 27 28 and people would just they would just leave they would they would walk out of the room or they would um argue with me like they would they would just like start screaming at me in the middle of presentations um and that kind of stuff and like obviously emails but still happen and now I
01:23:58
Speaker
I don't get anyone who challenges me directly to my face. Maybe I look more dangerous now. um Now, usually the questions are just, I'm just confused. Can you explain it? And I'm like, I would, I would love to explain this to you. what When you get a scathing email, what are they, what are they scathing about exactly? Because I feel like you've done a nice job of communicating, like don't kill the messenger. I'm just communicating this, what the science says. There's, there's so many, um,
01:24:25
Speaker
I would say early on, um I did a lot of education about Fungi and people are very, very weird about Fungi. And I would get emails about, um you know, don't encourage people to use Fungi, don't encourage people to get comfortable with Fungi because Fungi are really dangerous and really deadly and someone's going to get hurt. Ah, you mean spalted wood when you say that. Yeah. Or just Fungi and like people had a really hard time like breaking up like thinking it's a kingdom and they were just like well fungus is bad and and I don't ever respond to these emails just to be clear because I'm not going to feed the fire on that but it's really funny to sit there and go I wonder if they've ever had blue cheese or ever needed like antibiotics that was made out of penicillin like it's a huge kingdom uh and there's so much going on so we can't just throw all the fungi under the bus but um there's that there's there is a lot of
01:25:19
Speaker
I would say, I know wouldn't call it hate mail. i but There's a lot of deeply dubious mail that I get that says, well, you say all this stuff, but what is it like what does it mean? Like, are you telling me a Grishwick walnut? People think I'm coming for their walnut.
01:25:35
Speaker
like i I think there are some people who honestly think that I'm going to show up at their door and be and like, take their Walnut away from them. I don't care at all. What you do in your home and is entirely a bubble. In no uncertain terms, if you don't have a sensitivity to Walnut, sniff lines of Walnut. Who cares? But if you're sensitive, you're going to be sad. And I got a few messages from people on Instagram who are like, I'm sensitive to Walnut. now and I'm really sad about it. And I was like, well, yeah, I get it. That's sad. I'm not. So, but, um, Oh, so it telling chef labor. And then there's like, some people are just kind of out in left field and I think just need someone to yell at. And that's just, I can, I can eat somebody. run aable e
01:26:24
Speaker
as somebody who makes their primary living on the internet, I can tell you that people on the internet just want to fucking yell about the dumbest shit. And you're like, what, sir? so And I can confidently say, sir, because overwhelmingly, it is men. ah what What
Handling Criticism and Trivia
01:26:43
Speaker
are you yelling, like who are you interested at today? Like, what are we doing? What are we doing?
01:26:50
Speaker
I want everyone, I'm sure none of your listeners would ever write me hate mail, but should anyone who has previously written me hate mail um be listening to this, I want you to know that we I have a weekly, chilly night with my friends and we do read your emails a lot.
01:27:08
Speaker
This is amazing. Absolutely fantastic time. It's a children farm bread. Discussing you. I love it. love it. I have taken similarly, but on a public forum, I've taken to posting. I don't know what what threads is for and I refuse to be on Twitter, but um I've taken to posting like the the shittiest comments from YouTube on threads and just like letting people enjoy them. And it's quite entertaining.
01:27:37
Speaker
Hold on, Eric, I didn't know that. I have to read that. ah You're able yourself. I Google myself and I'm like, and I just read. It's incredible. a I do or I did for a while. I'll listen. Sorry, I'll tell you something very honest about myself, which is maybe a little bit exposing when um I started my business in whatever year was 2011, 2012. I wanted to buy Eric Curtis dot com and the guy who owned it refused to sell it to me.
01:28:04
Speaker
And ever since that day, one of my primary goals in life has been to wipe him off the front Google page, the first page of Google. And I have successfully done that, so fuck that guy.
01:28:19
Speaker
So that being said, um our sponsor spot today is from none other than our good friend, William T. Burkle over at WTB Woodworking. And so I thought,
01:28:32
Speaker
In, in light of last week, Paul wanting to know more about what WTB woodworking actually does instead of making a big joke about it. I thought that we could do a little quiz. I've got five questions here for you about things that WTB, uh, sells and or makes. And I thought, uh, we could just run through these. We got a multiple choice situation. So I'll feed you the question. I'll give you the, uh, potential answers and you two can answer accordingly. Oh, am I playing too? Well, so we'll see who wins. Oh, absolutely. Absolutely. ah Do I win something? You win the... You can just tell Paul he's dumb. Okay, I'll check it.
01:29:14
Speaker
All right, so number one, ah the lamello system invented in 1955 by the Swiss company of the same name is famous for creating what type of modern fastening method? A, the domino, B, the biscuit, C, the pocket hole, or D, when there's a little crack in the wood, so you rub some sawdust and wood glue in there and then a variable stains the surface, but it's okay, because nobody has to know.
01:29:42
Speaker
Am I allowed to glue it? you It's a quiz!
01:29:49
Speaker
Paul? Sarah? I'm gonna guess a biscuit. I was also gonna guess biscuit. It is the biscuit. They invented the biscuit joiner in 1955. Uh, okay. Number two, the temple tool company maker of premium Japanese full saws at affordable prices was founded by what American YouTuber? A the East coast craftsman, B West coast craftsman, C North coast craftsman, or D third cross craftsman. have but i I don't know.
01:30:26
Speaker
Third Coast Craftsman, Chris. It is Third Coast Craftsman, that's correct. All right, number three. ah WTB Woodworking sells not only tools but lumber and sheet goods as well. So Baltic Birch apply well-regarded for its quality due to in part its high number of laminations, has how many laminations in a three-quarter inch sheet? and theys A, 11, B, 12, C, 13, or D, 14.
01:30:54
Speaker
um Got some right next door. I could just go count. I don't know. Sarah, you guess first.
01:31:05
Speaker
11. 13. It is 13. Oh, it is 13. That was a good guess. That was a 50. I tried to give you the even numbers in there too, so it was a not. That was a total guess. I just got lucky. Do you know how many times I have to ID plywood? It is a really common.
01:31:24
Speaker
ID. You plywood in what went like the- The individual plies like peel them apart out of like a two by two inch square and ID the wood in a what? Really? Three cell-wise. Is that for a court case again or what? like how would I would do it for all kinds of things. A lot of court cases about illegal wood being used in the industry. This is fascinating. I need to know more about wood science in murder cases. ah All right, we've got two more.
01:31:51
Speaker
Number four. ah While we often think of fruit woods like cherry and pear as sustainable materials for woodworking, a number of nut trees are also used in fine fers fine furniture. Which of these is not a type of nut tree typically used in furniture? A, walnut, B, hickory, C, oak, or D, hazelnut. Hazelnut.
01:32:13
Speaker
Yeah, right? It is hazelnut. I have to admit that I formulated that question so I could make the joke Deez nuts, but then I decided that that would be more professional than that. So I went with a hazelnut. All right, last one. Summer fight.
01:32:31
Speaker
Chill epoxy, a company carried by WTB makes their Chill Micah powder pigments, which in my opinion have some very odd names. So which of these is a very real pigment color sold at WTB Woodworking? A, the smoking puppet. B, the spring break regrets. C, the smashed eggplant. Or D, of the dirty dog. What? What?
01:33:01
Speaker
I mean, Salty Dog is the color of my house.
01:33:06
Speaker
so So... You going dog? I'm going eggplant. What do you got, Eric? Is that your final answer, Sari? I... i e Yes. They are all very real names of colors. Oh, we sell. Way. yeah three yeah Sprigerets is my favorite one, I think. Is that like a pew scholar? Like what? hey I honestly, I couldn't tell you. I just saw the name and I was like, that's amazing and terrible. The only one of these start of games I've ever been good at is there was a corn star or My Little Pony. ah Guess the name. And I know we were doing it for the next ad read now. I love My Little Pony and I just was great. ah Oh, okay. That's amazing.
01:33:55
Speaker
ah That could have gone many different ways.
01:34:00
Speaker
So now we're going to do a little Q and&A because we asked you guys about questions. And so we're going to go rather quickly through the Q and&A before moving to the after show. um Ready? OK, I'm sorry. i' like I'd like to know more about the chemistry of wood aging, meaning's meaning like the chemistry of how cherry darkens or how purple heart turns brown. ah Can you tell me more about that process?
01:34:24
Speaker
It's called oxidation. um So wood in contact with air, ah things happen. In particular, extractives oxidize. And so those colors that you're talking about, all wood has extractives, but we use prettier woods, right, for furniture because they're pretty. Well, cherry is a red color and that's an extractive and the purple in Purple Heart.
01:34:48
Speaker
is an extractive and they and they oxidize over time so just contact with the air there's nothing you can do about it right you can put finishes on it to slow it down but you can't stop it and so purple heart that pigment is not light stable and it's not air stable and it oxidizes to brown it will do faster in light and cherry is the same it just they oxidize and eventually cherry does turn brown over time three pigments are not they're produced by the tree to be inside the tree yeah anddo and they don't need to be stable in lighter air.
Wood Oxidation and Revisiting Risks
01:35:23
Speaker
And so when you expose them, they go through a natural process.
01:35:26
Speaker
God, I love that. That is a really good point. Can I ask an ignorant question? Because I know I refer to the color, the change in color as oxidation, whether that's due to an oxygen in the air or light exposure, because in my dumb furniture maker brain, like they're the same thing. But like cherry will age faster in direct sunlight.
01:35:49
Speaker
so Are they the same thing? And we're just grouping them. Let me gather let me guess. Let me, sorry, let me guess. And you're turning me from right. The sunlight raises the temperature, which favors a faster chemical reaction. So it oxidizes more quickly. Is that my guess? Uh, I'm sure that's happening, but it's not the primary factor. Okay, go ahead. UV light.
01:36:13
Speaker
degrades the lignin and it grays it. And that's why your decks turn gray. There's nothing wrong with the wood, right? Like a gray deck is still probably a perfectly fine wood, but it grays because of UV and that affects how the lignin is. And so then that graying affects how you visualize the color.
01:36:32
Speaker
Interesting. Okay. So they are they are very different processes. I just assumed that they were one and the same. Well, did does the sunlight speed up ah like in the case of- Yeah. For example, cherry. right If you take cherry, like yeah the the common problem of like cherry plywood with a quarter on it, right? So where the quarter is, by the time you get home and the cherry plywood is in the back of the truck, it will be a different color than where that quarter was. So it has to speed it up in some capacity, right?
01:37:01
Speaker
Well, the light, again, that's the UV degradation. It's the happening as well. Okay. All right. And that leads to faster oxidation. That degradation somehow enables the oxidation to proceed faster. Well, part of it's the graying, right? So it's changed' like physically changing the color of the water stain. I am 100% certain it is also dealing with the oxidation, but that's getting into a section of wood chemistry that I am not qualified to talk about.
01:37:26
Speaker
Great nursing. That was so good. I love what you said about like Woods concerned about being on the inside of this tree. Yeah, that's a great point. It's a great point. No, it is not trying to grow itself for furniture. It doesn't care about you. Nor is the pig trying to become bacon, and yet here we are.
01:37:43
Speaker
And so relative risk is only 18%. Okay. Listen, if you guys um ever have me back on this show, um, you know, cause you get not enough hate mail and you want more, um, I think we should all come into it with a plate of bacon and we could just be like violently hundred percent as we talk. i And I will have it on a plate of Coca-Cola just to see what happens. All right. Question two, uh, milk paint. Can we add milk paint safety to the discussion? Is milk paint safe?
01:38:13
Speaker
I am not a chemist. I am not qualified to answer this question. I did look up um what milk paint is made of and it seems like it's made of casein, which is milk protein, lime, and natural pigments. it They say it's non-toxic, environmentally friendly, but they say that a lot. so i i mean All I know is that a lot I'm friends with a lot of toy makers, a lot of natural toy makers, and it passes their safety testing.
01:38:43
Speaker
They make it themselves though, so they have to get their form and they have to send out their formulations for testing and it passes, but so do a lot of things. So yeah again, good I'm not a chemist. Regarding making it yourself, I make my shellac myself because I take shellac flake and I dissolve it in ever clear grain alcohol, which is just methanol meant for you know or sorry ethanol and with plus five. It's 95% ethanol and 5%, I don't know, maybe water. so For anyone who's gone to college and has ever cleared hair. Yes. So I do that because i I know that if you just buy shellac at the store, it's usually in denatured, some form of denatured alcohol. And what denatured means is very loose. It can be methanol, it can have other nasty organics.
01:39:29
Speaker
And I don't really want to be spraying that or using that. So that's why I make it myself. So it sounds like with your milk paint buddies, they know that what I put in is this and therefore I know the safety of it.
01:39:42
Speaker
Can I just make one point about milk paint specifically, but natural pigments as a whole? like we We say that and like that's great, that's wonderful. ah The reason that milk paint, read like barn red, is a thing was because when they were using milk paint to seal the outside of barns, barns have a lot of rusty tools in there and the rust prevents mold from growing on the wood.
01:40:05
Speaker
So, bar and red came from literally banging off dried rust into milk paint and mixing it in as a pigment. And we all know what rust does when you inhale what's going on there. So, just to note, natural pigment's great, but also rust will fuck you up. So, natural doesn't mean safe in every context. Okay. If it did, you should just go lick some poison ivy and see how well
Safety Measures and Woodworking Spaces
01:40:31
Speaker
that...
01:40:31
Speaker
we go ah Next, I have developed wood allergies over time. It's honestly really awful, and I've considered giving up on woodworking because of it. It's not a question, it's just a comment, but I thought it bared reading. I feel bad for that person. Sorry about that. I want a person, if you're listening, I am allergic to everything under the sun.
01:40:51
Speaker
and I can still woodwork. What I have done is I ever since I started developing the allergies right I have a professionally fitted I we have a OSHA like group at the university I have a professionally fitted mask I make sure to shower when I'm done woodworking and all of my stuff as point of collection and as much as it pains me to do this uh best tool type stuff because it's got those great vacuums and everything hooks up to it it's so expensive but i have i've tested it on myself i'm a canary coal mine
01:41:25
Speaker
I have sanded with their sander and their dust collector hooked up to it without a mask on, which with any other sander um would have me looking like a puffer fish within a five minutes. And after five minutes with that, I was the tiniest bit itchy. And so it's incredible. Can do it. It may just cost more.
01:41:48
Speaker
and yeah will good I was just going to say, I will die on this hill. Festool's dust collection is better than anybody else's out there. and like I've said that anecdotally, but that's proof of what you're saying. is like You can actually woodwork with it ah with the with the HEPA filters attached.
01:42:07
Speaker
I do want to say this isn't all or nothing. You know, everyone's always looking for a recommendation. What do I do? It depends on where you are. Like I think series on the the the more careful end of what I've heard. And I'm, I'm like kind of in the middle. I definitely have HEPA stack on. I have point of collection on everything. A huge HEPA stack coming off my Cyclone. And I have a HEPA filter on my shop vac that I always attach to my sander when sanding. I open the doors to allow the fine particulate out. But I don't wear a mask that often, and only if I know I'm doing something really bad. So like that's an example of, like okay, my my allergy risk is much lower and has been for 20 years. like I think you know the the cat's out of the bag. I'm not particularly sensitizable. So I take ah i take you know some steps that are easy, but it's you don't you don't have to always go haul hog if you're not sensitive.
01:42:59
Speaker
But you'll be sad if you're not sensitive and you don't take some very simple steps and you become sensitive. That would be a real tragedy. Can I ask, in this vein for this person, I was i was wondering how wood dust versus, say, hand tool work changes ah if you're planing and using chisels versus using saws and and sanders. Is that a thing? I personally have no issue until there's fine particulate. So I can chisel all day.
01:43:30
Speaker
Um, but you start getting into like fine Japanese hand saws and or any that lower level dust. The finer the dust, the more it irritates me personally. Sir, you're a good, a good example case. How about hand planing? Does that get you? I have no issues with hand planing at all. Amazing. Yeah. Even like, I will say even like hand sanding with like 80 grit, like just a little bit of that usually is not enough to set me off because the particulates are so large.
01:44:00
Speaker
terry You're like a line in tool. You're like a fine desk measurement tool. That's really incredible. So like, I mean, we all know that like a hand tool shop has less dust, but it's really interesting that you being allergic to basically all the woods, you can sit there and hand plane all day and not a problem. So there is there for somebody like this person. There's hope you just might have to come at it from a different angle.
01:44:24
Speaker
It sucks for my students because I could tell if they haven't had the likes, if they haven't, they because, you know, they don't want to hook the vacuums up to the Sanders because they're 19 and the world is their oyster. And I can kind come into the shop and I can come in the next day and go, who didn't use the vacuum? Thanks to you, we aren't having class today because I can't be in here. So, well done. Gosh. Okay. Wow.
01:44:53
Speaker
Okay, ah next question. It's not easy to put on a respirator for a little task here or a little task there. I'm a hobbyist, so I'm not woodworking 40 plus hours a week. Am I unnecessarily increasing my cancer risk?
01:45:05
Speaker
I would say based on the data reviewed today, probably not. You're low exposure and the absolute risk is very low. I mean, yes, there the in some small, minute way, you probably are, but it's so minute, I wouldn't worry your pretty little head about it. Related to that question.
01:45:27
Speaker
I will sometimes forgo a mask doing something. like as it's I power carve quite a bit. And if I'm power carving for a long time, of course I'll wear a mask. But if I'm doing three minutes of work, I might not put one on because I in this i could be speaking out of pure ignorance here.
01:45:44
Speaker
But the point of the mask is to filter out the fine dust particulate. And because of this stupid fucking thing I have on my face, the mask never seals. is that a real that it That has to be a real like quantifiable difference, right? That's one of the questions, too, Eric. That's another person asked the beard question. Go ahead. pray we can getby You guys, at my university has a beard chart.
01:46:07
Speaker
They send us before we do our testing and they label all the different types of fears and that which which ones you can have and which ones you can't have. They gave them names like the pirate, the villain, but like it all the different, why and like which ones will interfere with the mask and they send you this chart.
01:46:26
Speaker
before you get tested. And they're like, these 10, like are fine. These 10 are not. And then the villain I just want you to know says it depends. Like someone had a really good time making this chart. That was an Eric is the pirate, please.
01:46:45
Speaker
Okay. Um, okay. So it does make an actual difference. Yeah. Yeah. Okay. Breaks the seal. It's like N95 same with hospitals and COVID and N95 any fee out here breaks that seal. Yeah. Um, what are the top? Okay. This, this one, sorry, you're going to love. What are the top recommended food safe finishes? So, okay.
01:47:04
Speaker
that What they mean is that the thing I'm putting on the board is not going to hurt me. Like the substance, the oil is not toxic to me, but you have a different view on what food safe means, right? Which is allow the wood to be hyperscopic. Yeah, so I don't think you should put any finish on a wood, but let's take it at its face value what finishes.
01:47:25
Speaker
are non-toxic. There's like two answers to this. And the first one is they they wouldn't pass safety regulations to be like a consumer finish if they weren't safe when cured, right? So they all have to go through that testing. So in theory, they're all when cured, not dry, cured, they're all safe.
01:47:49
Speaker
But now we all care about plastics, right? And microplastics and things like that. And a lot of finishes are just a thin the plastic layer. yeah And so you are putting something that could give you microplastics now in touch with something that will be in touch with food.
01:48:07
Speaker
And a lot of those finishes, like we know that plastics leach, right? They leach chemicals. We know they leach it more when they're hot. We know they leach it more in contact with water. Like there was that old new study that came out about water bottles. And even when it's not hot, just like the water being in the water bottle, you know, you're leaching plastic, whatever. Uh, there's a hundred, a hundred thousand plastic nanoparticles per water bottle without a new, a hundred thousand per bottle.
01:48:36
Speaker
putting that on your wood in some instances and then you're going to eat out of it. And so you have to then think, okay, so if Let's pretend that the antimicrobial nature of wood does not exist and you have to put a flinch on it. If you were going to do that, I think you would want to be looking at natural oils that have some sort of solvent to help them dry. And so yes, obviously the solvent is toxic if you sniff it, but after it, you know, the thing cures and the solvent flashes off into the air and then the end user has this hardened like linseed oil, which, you know, you can get food grade linseed oil.
01:49:13
Speaker
um And it's fine and you can do it without the solvents. You could just use raw linseed oil on your wood But it takes it could take over a year to cure and it reeks When it's curing and a lot of people find that smell quite offensive. So there's like a you have to You have to think about it. Do you care about plastics? Like, if you don't care about plastics, then I mean, shove a polycrylic on there and live your life, you know? Oh, I mean, prop probably is laminate like that bitch. no soon Speaking about risk, the the amount of plastic the amount of plastic coming off that cutting board is probably a drop in the ocean of what you're exposed to from other routes. But I mean, why add to it? Okay. ah to to To follow up on... The answer about the the drying oil, um one of the oils that's popular that I've used is um Osmo Top Oil. It's been certified as food safe by the German equivalent of the FDA. And it's exactly what's already said. It's it's um a bunch of food safe oils and waxes in ah odorless mineral spirits that flashes off completely. How do I know that? Because I i i looked into whether odorless mineral spirits actually leaves a residue of any form when it flashes off. It does not.
01:50:25
Speaker
So all you're left with is like a highly polymerized, you know, food safe oil and wax. And the same is true for shellac. as I mean, shellac is made by bugs, like the lac beetle. And if you dissolve it, it never clear, you know, the solvent is non-toxic. Well, ethanol is toxic, but, you know, at least relatively non-toxic. And so those are two very common reasons. And I guess, you know, pharmaceutical grade mineral oil,
01:50:50
Speaker
I guess mineral oil, by the way, is many different things. It's made by the like a petroleum distillate usually, and it's very, very variable. Which fraction is it? Which distillates are in there? So I always go for pharmaceutical grade because I assume that's the clearest, but something like one of those three would be, I guess.
01:51:08
Speaker
You know, but but I like the first answer. Why don't you leave it? You know, don't worry about a finish. Let, but the wood already fine. Think about even if, even if you disagree about the finishes in general, everything's expensive. Now think about it as a cost saving measure. You don't need to put anything on your cutting boards. So I just saved you the like what 20 bucks and time time. You can charge the same amount, but you put less time in. I've raised your profit margin.
01:51:37
Speaker
See, i love I love that you know how to sell it to these people too, because you can't just be like, don't put a finish on wood. You have to be like, no, no, no, it's going to save you money. It's going to save you time. Listen, and that's wisdom right there. I teach woodworking to college students. do you I love my students dearly, but do you know the kind of student that takes woodworking in university? They're the kind of students who I very lovingly call them my don't tell me what to do students. And so I am aware that the old working population is not a population that is real good with sitting down and doing what they're told. So instead, let's talk about how you can make more money by doing less work.
01:52:20
Speaker
Fantastic. How about sealing off your shop from your house? Is that a big, there's a question about that. It's about half a page long. I'm not reading it. Uh, how important it is. Is it to seal off your shop from fine particulate from your house? Oh, pretty important. Yeah. Yeah. You would not like you would, would work in your bedroom. Although I've done that. It's a bad idea. It doesn't weigh. Yeah. I ain't just going to put that all day.
01:52:46
Speaker
you You probably don't want your kids exposed to it all the time, right? So I guess, yeah, you should probably do your best to try and, okay. You don't need like a part, my garage shop, I have a door, you know, that the door works. Yeah, so it doesn't have to be like crazy, yeah. No. Yeah, maybe don't live in the shop, I think.
01:53:07
Speaker
Yeah. Does wood baking, like does kiln drying or caramelizing, what do what do they call that? um There's a word for that when they overheat it. roast and like roast Roasted maple. Does that alleviate any of the allergies or toxicities of extractive wood? No, absolutely not. In fact, I saw a paper that said it made them worse. The wood was more apt to disintegrate into little particles because you've destroyed more of its structure by overheating it. Is that, yeah, that squares? Interesting.
01:53:41
Speaker
How about wood burning, like pyrography? Does that carry any considerations or concerns? You are flashing off some extractives when you do that. So, ah you know, don't do it on something that maybe you're concerned about the extractives, but it's going to be different kinds of extractives that come up with heat versus water. And so i it's so little with pyrography. Like now you're in a Europe, you probably aren't having a toddler do pyrography. So my concerns now about toxicity are evaporating along with the smoke.
Wood Toxicity and Exotic Woods
01:54:14
Speaker
Uh, it's so little and you're doing it usually for, you know, it's just, it's so like a little thing of smoke. If you eat smoked meats, I would argue that your exposure to carcinogens and, and wood smoke is already plenty. Like your little pyrography is not doing anything on top of that, that you aren't getting from like smoking meats. Okay. All right. Last two answer. What is the most popular species that people use that is of most concern in your opinion?
01:54:45
Speaker
Purple heart, say purple heart, please just say purpley to walnut. It's probably purple heart. God damn right it is. It's probably purple heart, yeah. Tell us a little bit why. It's because I see it in teething toys. Over and over and over. You weren't being anecdotal about that? You're being dead ass serious? No. Really, it's commercially available. People can get it and it's a beautiful color.
01:55:15
Speaker
And I have seen it far too often in like little grippy teething toys and rattles. And in glue ups particularly, there's always like a Purple Heart bloodwood maple. It's a really common trifecta.
01:55:30
Speaker
Um, and it's, again, I don't care what you do as a grown adult at all, but I do care what you give to babies. And when, you know, usually it's just like a doting grandparent who like has lovingly made this thing And it's like Purple Heart, it's always fucking Purple Heart for some reason. I just always, it's my beautiful Purple Heart. There's one thing we know. Yeah. If there's one thing we know about Young Woodworkers is it's always fucking Purple Heart. Oh, we let them raise up. It's the first thing they ask me. Hey, when's Shopical Woods week and are we going to get to use Purple Heart? And I'm like, I don't fucking want to have this conversation. Stop it.
01:56:11
Speaker
ah and sir Just to finish your answer, what's the risk to the child that they'll develop an allergy very early to this? there are A lot of those beautiful tropical woods have water-soluble extractives in them. and so again and i've got Again, I've got charts. You can look up and there's a lot of actual data on it, but ingestion in a small body is a concern. but Is it a concern because of toxicity or allergies or both? Toxicity.
01:56:39
Speaker
ah like actual ingestion toxicity. Okay, so there are extractives that just don't, it has nothing to do with the immune system analogies. Yeah, there are some that can actually affect a mammal, of larger mammals. Okay, good to know. And last question, and I think this is a great way to end because you are Dr. Spalted. um What about using spalted material for cutting boards? Are spalted wood safe for humans?
01:57:06
Speaker
I love this. I have tested spalted wood over and over and over again. You know how many zebrafish we haven't killed testing spalted wood? Spalted wood from everything that we have tested, now I'm sure there's some out there that we haven't tested, ah is utterly and completely benign.
01:57:25
Speaker
um I still would not necessarily recommend highly spalted wood for cutting boards because it's very soft and I think your knife will just go through into your countertop. But man, let me tell you, nothing beats a nice piece of figured wood with some like light to medium spalting on it. Sanded to 400 grit. ah That is some of the nicest stuff you can get.
01:57:47
Speaker
I love your passion for it. ah Does the degradation that occurs with heavy spalting you, it gets punky? That's like guess the word we like to use. Does that lead to a change in anything about the bacteria or food getting in there? Does that change any of that equation? It'll make the wood more porous. It'll move water faster in certain areas. And I would say if it gets real spalted, you could see um things just kind of shoot all the way through down to the bottom and not stay in the woods. So you've really got to watch the white rot component.
01:58:14
Speaker
All right. So you don't want it like punky to the point that it's like degraded, like structurally. If it's a sponge, it's, it shouldn't be a cutting board. Okay. But like all my cutting boards are salted and a good rule of thumb. Like, you know, it can be, it can be clearly white, right? You can have some of that white rot, but you, you wouldn't want to be, if you can like chip it out with your fingernail, it's too soft. Great. Great. Great.
01:58:43
Speaker
Well, folks, our longest episode ever, bio. Without a lot out. But this was so important to do, I think. Tari, you're amazing. The breadth of knowledge you brought, the clear-cut answers, the ability to round decimals, ah to give like really like great answers to these things. Thank you so much. Oh, you guys were awesome. This was fun. This is fantastic. Thank you.
01:59:12
Speaker
Next day soon, next time. We're all sitting around when we come out to Oregon at some point. We're gonna sit around to play the bacon together. and That's not what we're gonna do with us. Yeah, I just, ah again, I appreciate it. It's rare to have so much dedicated time from such a learned ah professor. Thanks again. And anyone who wants more, um we're gonna be talking more in the after show. You know how to get that. Just subscribe to our Patreon and we'll we'll see you there. Thanks again, everyone. Amazing. Thanks, friends.
01:59:42
Speaker
by Bye!