Wood Toxicity and Dust Safety Guide

Every woodworker breathes some sawdust. Most of the time it is just a nuisance: a dusty nose, a sneeze, a film on everything in the garage. But trees make natural chemicals to fight off insects and fungus, and some of those chemicals bother people too. In our Fort Myers shop we cut, plane and sand dozens of species every week, from Florida camphor and mahogany to Import woods like cocobolo and wenge. This page is what we have learned about working them safely, plus a quick rating for every wood in our guide.

How wood dust reaches you

There are three ways in. Fine dust from sanding and routing floats in the air for a long time and gets breathed deep into the lungs. Dust and sap that land on skin, especially sweaty forearms, necks and faces, can cause rashes. And splinters push wood straight under the skin, where a few species are known for wounds that turn red and heal slowly.

The finest dust is the biggest concern. Sanders, and especially drum sanders and random-orbit sanders, make particles small enough that you can't see them hanging in the air. A saw cut makes bigger chips that mostly fall to the floor. Wood dust is treated as a workplace hazard in its own right, and years of heavy exposure to hardwood dust has been linked to cancer of the nose and sinuses. That is a reason to control dust with every wood, not just the ones with a reputation.

Irritants and sensitizers are different problems

An irritant bothers almost anyone who gets enough of it. Think itchy skin, watery eyes or a scratchy throat that clears up a day or two after you stop. More dust means a worse reaction, and less dust means less reaction.

A sensitizer works through your immune system. The first few times you may feel nothing at all. Then, after weeks or years, your body decides the wood is a threat, and from then on even a small amount can set off a rash or an asthma attack. That allergy usually does not go away. This is why some longtime woodworkers suddenly can't touch a wood they have used for decades, and why rosewoods, cocobolo, teak and similar woods deserve respect even if they have never bothered you.

A few species have reports that go beyond skin and lungs, such as nausea, headaches or dizziness. Where those reports exist we list them, and we never add a claim we can't back up.

Protecting yourself in a small shop

You don't need an industrial setup. You need to catch dust where it is made and keep it out of your lungs.

• Collect at the tool. A shop vac or dust collector hooked to your sander, saw and router catches most dust before it spreads. Add a ceiling-hung air cleaner if you sand a lot.
• Wear a real respirator for sanding. A loose paper mask doesn't seal. A fitted N95, or better a half-mask with P100 filters, does. For woods we rate High or Severe, wear it for any machining, not just sanding.
• Cover your skin. Long sleeves and nitrile gloves keep oily dust off your arms and hands. Wash up before you eat, and change your shirt before you hug the kids.
• Clean with a vacuum, not a broom or an air hose. Blowing dust off a bench puts the finest part right back in the air you breathe.
• Pay attention to your body. A rash that shows up a day after working a certain wood, or a tight chest that comes back every time, is your cue to stop and talk to a doctor. Write down the species so you can avoid it later.
• Finished wood is a different story. Once a piece is sanded, cleaned and sealed, most of these concerns drop away for everyday use. The risk is mostly in cutting, sanding and handling raw wood and sawdust.

Florida notes: heat, humidity and working outside

Working wood in Southwest Florida has its own wrinkles. Heat and humidity mean sweat, and sweat helps dust and sap stick to skin and soak in. Many skin reactions start where clothes rub: wrists, collars and waistbands. Rinse off soon after a session and don't sit around in damp, dusty clothes.

A lot of local work happens outside or in an open garage. A breeze helps, but it doesn't replace a respirator when you sand, and it can blow fine dust right back into your face. Set up so the wind carries dust away from you.

Some Florida trees have sap that is the real issue. Mango and cashew are relatives of poison ivy, and so is poisonwood, the native cousin of chechen. Fresh-cut wood and sap from these trees can cause rashes in people who react to poison ivy. Silk oak, a Domestic Invasive here, has a similar reputation. Storm-felled and yard logs are wetter and sappier than kiln-dried boards, so wear gloves when you handle green wood.

Mold is the other Florida problem. Slabs that sit wet grow mold and the fungi that cause spalting, and sanding moldy or spalted wood puts spores in the air that are hard on the lungs. Dry wood well, keep it off the ground, and wear a respirator when you sand spalted pieces.