Toxic woods + laser cutter use?

  1. Got asked to engrave some walnut on the laser
  2. Thought I remembered seeing that on the toxic woods list
  3. Couldn’t find the toxic woods list. Found the woodshop policy that the board voted on back in March, and it hadn’t been worked into the wiki for some reason yet, so I did that:
  4. Question still stands, especially with all the ventilation questions, is it safe to engrave on things like walnut?

Googling around it seems like inhaling wood sawdust is WAY more dangerous than inhaling smoke from wood, unless we’re trying to burn poison ivy or something. Anyone want to share an opinion?

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Most sensitivity to walnut is due to an allergic reaction to a couple of different proteins. Proteins do not survive burning or vaporisation well enough to be a huge sensitization risk. There definitely are always solid particles ablated during engraving, those carry the same exposure risk as sanding, scraping, drilling or other dust generating processes. If the exhaust fan system is working reasonable well, a person is no more likely to have any reaction laser engraving walnut than they would when using good practices in the wood shop.

Many places sell walnut specifically to be laser engraved.

I would only recommend a couple of things, similar to what should be done in the wood shop.

  1. Clean up thoroughly afterwards, don’t leave scraps inside the building but take them out to the dumpster in the alley. Vacuum out the bed with the shop vac so that no small particles are around where the next person would not expect to encounter walnut dust.

  2. Alert anyone in the front area before you start, and anyone that comes in while you are running a job that if they are already sensitized they may want to steer clear until you are finished with clean up.

  3. Let someone else know what you are doing so they can monitor whether you are lying on the floor foaming at the mouth or similar.

Mike B


You’re like an encyclopedia.

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Mike-lo-pedia Americana, in one volume




I’d say that list is very inadequate. There are at least a dozen woods that are generally available that have a higher allergen/toxicity concern than walnut or purpleheart. This needs reviewed.

Have we ever had a complaint about allergens or someone who had a reaction to a wood being used in the shop?

We’ve only ever had one complaint. Thanks for answering the original post, Mike.
Some say this list may not be adequate, but it’s possible they may not be knowledgeable of the usual suspects. For a full read, check out the article posted on the woodshop doors.


So is the list on the door the one we need to go by or the list on the wiki? Or both? Because the wiki list would let me use cocobolo, but the “usual suspects” list wouldn’t. BTW, contrary to the Woodcraft list, cocobolo is a known allergen ( I’m not trying to be difficult, but this has impacted several of my projects. I’d just like a definitive policy. Is there another class for the authorization to use the subject wood on tap? I don’t see one on the schedule.

Kim raised a question for the group about exotic/toxic woods and the laser cutters.

We (@fablab) will try address this question directly and guidance via the Wiki. The wiki is the definitive guide on what can be cut/engraved on the lasers.

Much of this will echo what Mike has already stated. It is my opinion from the vast amount of research (about an hour of googling) seem to support that a large factor to the allergic reactions due to coming contact with dust (large surface area), directly handling the wood.

The laser do not produce saw dust, mostly combustion products. The ventilation system (when working and applied correctly) vents outside.

To restate the my position (Fablab) until someone replaces me. Follow the wiki list of acceptable material in good faith, clean up after your self. The only amendment I will make to the wiki about the fablab area. Any material that is listed on any MakeICT list of toxic/exotic woods should not be left in the Fablab open area (outside lockers) while not being worked on. To protect other members from contacting it. Don’t leave it in the scrap pile.

I will let the board/director speak to the co-working area. I would expect no sanding/machining of the wood that might produce duct would be reasonable.

I would ask a moderator to lock this thread, and any further discussion about what should and should not be on the wood shop list of acceptable material should be restarted on another thread.

If anyone disagrees with my stand on the laser material specifically please email and we can setup a time to meet and go over this in more detail.

I’m not sure that leaving a piece of walnut in a locker would cause any issues, but yeah, it probably would be a bad idea to sand it at the co-working tables for a number of reasons. That would apply to every kind of wood, whether it is on the list or not. Taking reasonable precautions to avoid causing foreseeable harm to others is good policy, but taking extraordinary steps to avoid extremely unlikely issues isn’t. If someone is so susceptible to a reaction that they’d get sick from being in the same area as a piece of walnut furniture, hanging out in a building with a wood shop is a really bad idea in the first place.

In other words, if you’re highly allergic to peanuts, don’t go to Texas Roadhouse.

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It’s possible that our access policy for the woodshop is out of date. The policy on the door, showing the list of hazardous woods, is our most current policy. It was approved by the board back in March.

We know that there are a TON of different resources giving different accounts of toxicity, but the information provided by wood science expert, Larry Osborne, has given us a pretty fair and concise list of woods to treat more reverently.

And this all has to do with dust. If you’re not making sawdust, there’s really no harm.

For more information on this, we invite you to take part in one of our hazardous material training classes usually offered at the dnd of every month. There, you’ll also be granted authorization to use said woods in the woodshop, too.

"But it’s on the non-hazardous list in the wood shop!"

My last post was completely inappropriate. My apologies.
I have edited the image to make it more appropriate: