The Healthy Woodworker

Who cares about the health when feeling well?

And you thought the woodworking shop only had physical dangers? Being safe in the shop is important, but what about the long term effects wood, dust and chemicals can have on your health?

There are several potential sources of health problems in a modern hobby woodworking shop:

fine dust from powertools (cutting, sanding, sharpening, routing etc.) suspended in the air that we are breathing. This can cause allergic reactions, but also lung damage if we breathe enough of it
dust/shavings from (certain species of) wood that can cause rashes and allergic reactions if it comes in contact with our skin
finishes and solvents - and their fumes

Protect yourself from dust and toxic wood

I suffer from allergies. I am hypersensitive to dust and dust mites, furry animals, many chemicals - and certain kinds of wood. Reactions vary from light itch to severe rashes requiring steroid treatments for many months. So I have to take precautionary steps if I want to keep on woodworking:

Spalted maple bowl

I always wear a Lee Valley Turners's Smock when turning, or long sleeve shirts for sawing, grinding/sharpening or any other work where dust and chips can get thrown against my skin (arms)
I always use a dust collector when working with dust-producing power tools. I also use a Triton PRA001 Powered Respirator in addition to the dust collector so I don't have to breathe any dust.
When I find a species of wood that I am overly sensitive too, I stop using this kind of wood for good. One of the worst wood I have ever encountered is spalted maple. It must be the fungi in the spalted wood - it caused me respiratory problems - and rashes too if I remember right. Spalted maple is a very beautiful material for bowls, but I will stay away from it in the future - even if I today have a good dust collection system and a respirator. Regular, dry maple does not cause me any problems.

Protect yourself from harmful finishes and solvents

When working with finishes and solvents, I always use gloves and make sure I have sufficient ventilation. Sometimes I have to open the garage door or do the work outside. I only use very small amounts of finishes and solvents, so I have not found the need to invest in special respirators for these.

If you are using more than few drops at at time, my recommendation is to get OSHA approved splash goggles so you don't get any chemical splatters in your eyes. I will also recommend getting a rubber apron to use when you are finishing larger items. In my shop I always wear a protective jacket or apron when I am doing finishing work.

Some terminology you should know first...

Evaporation rate: How fast the liquid will evaporate. E.g. in a humid climate, it can be beneficial to use a solvent or finish that has high evaporation rate - it will then dry faster.
MSDS: MSDS is short for Material Safety Data Sheet. It is a safety document stating all known hazards, how to work with the chemical safely (e.g. what kind of protective equipment should be used), chemical properties like flash (or ignition) point, toxicity, reactivity, storage, spill clean up. It also lists first aid measures as well as emergency contact numbers for further information. It is not so much intended for the consumer as it is for an occupational or work place setting. In the US, OSHA requires that MSDS's be available to employees working with potential harmful substances in the workplace. If you would like to review an MSDS for a certain product, you can call or e-mail the manufacturer. Some manufacturers also have MSDS's available online. I suggest you get these documents and take a look at them. They contain valuable information if you care about your own health.
Organic solvent: A solvent containing carbon compounds. Acetone, alcohol are examples of organic solvents. Most organic solvents are harmful to the human body.
Solvent: A liquid that can be used to dissolve a solid (e.g. dissolve glue you want to remove) or thin a liquid. One common example is water.
Spontaneous combustion: Rags etc soaked with certain solvents can self ignite because the drying is an exothermic process ("gives off heat"). Many oil finishes can cause spontaneous combustion of rags if they are not handled properly.
Stripper: A stripper is a chemical (or mix of chemicals) used to remove a finish. Stripper is also a term used for the performer of a certain human activity, but it is beyond the topic of woodworking, so I will not describe it...
Thinner: Another word for a solvent that can thin other liquids like paint, oil finishes.

Common solvents and thinners in a wood working shop

Below I have listed several common solvents and thinners used in a woodworking shop - and some of their hazards. Since these are usually the most dangerous chemicals in a woodworking shop (because of their volatile nature), I have decided to mention these to raise awareness.

The list is not extensive and you should refer to the handling and safety instructions on the product itself and the MSDS issued by the manufacturer. Often the manufacturer will list their MSDS's online. Many of these solvents are also part of the finishes we use (e.g. varnishes, wipe on finishes), so the info will apply to all products containing these solvents as well. Don't flip out as you read about their dangers and toxicity - if used in small amounts and with appropriate safety gear - their harmful effects are almost eliminated.

I will also refer you to OSHA's Home Page - click on W on the A-Z index and then go to the Woodworking eTool. They have a section on Finishing/ Chemicals that is worth reading. The information is geared towards the work place, but the hazards are the same whether you are using e.g. toluene at home or at work.

Oily rag disposal can with self closing lid

WARNING! If you have children that could access your shop, please store your solvents and finishes in a locked cabinet! Although most solvents and finishes today are sold in containers with "child safety" lids so small children cannot open them and drink the content - accidents can still happen.

When disposing of rags, paper towels, disposable brushes and gloves that has been used with your finishes and solvents - do it safely so you don't cause a fire. I use an oily rag can to put this stuff in. It is made of metal with a self-closing lid. If something should self-ignite inside the can, the fire will extinguish by itself as the closed lid hinders oxygen/air to enter the can - and oxygen is necessary to keep the fire alive. I bought mine at Harbor Freight, but they don't carry it anymore. McMaster Carr still does.

Acetone

Acetone is an organic solvent used for paint thinning. It is also used as a stripper to dissolve and remove paint, epoxy resins, adhesives (e.g. white- and yellow glue, rubber cement), grease. It is also a component of super glue removers.

Because it evaporates easily, it should not be spread on a large surface area as fire and health risks will increase dramatically! Always ensure adequate ventilation to avoid inhalation and reduce the risk of ignition.

Flammability: Extremely flammable. Never work with acetone in the presence of an open flame or hot surfaces. If the vapor concentration is high enough, a spark (e.g. from static electricity) can cause explosion.

Toxicity, inhalation: Toxic. Inhalation can affect the central nervous system, and repeated exposure can cause irreversible neurological and physiological damage. Indications of acute exposure are dizziness, headache, nausea, eye-watering, drowsiness, numbness in fingers, arms and legs. If you experience any of these symptoms leave the work area immediately and get fresh air.

Acetone should always be used with adequate ventilation (e.g. cross ventilation) to avoid vapor buildup and inhalation. And if you do a lot of work with acetone, a respirator rated for acetone is a worthwhile investment.

Toxicity, skin absorbtion: Notice that acetone can easily be absorbed through the skin, so protective gloves should always be worn. If you use a lot of acetone for some reason, you should consider getting the thicker butyl, neoprene or latex gloves. Nitrile and PVC gloves are not suitable - acetone will permeate these materials. Thin, disposable (medical type) latex or chloroprene gloves can also be used for shorter time exposure. If you are allergic to latex - use PVC or nitrile gloves underneath the latex glove.

Eye contact: Splash may cause redness, irritation.

Ingestion: Harmful. May cause headache, nausea, dizziness, irritation of mouth, throat and stomach.

Alcohol, denatured

Denatured alcohol is ethanol (alcohol) with toxic additives (e.g. up to 10% methanol - or wood alcohol) so it cannot be used for human consumption. It is also exempt from alcohol tax, so it can be sold at a lower price. It is used as a solvent - e.g. in shellac and shellac based products, and is an effective de-greasing agent.

Flammability: Highly flammable. Never work with alcohol in the presence of an open flame or hot surfaces. If the vapor concentration is high enough, a spark (e.g. from static electricity) can cause explosion.

Toxicity, inhalation: Due to its denaturation, denatured alcohol is toxic. Inhalation (acute exposure) can cause dizziness, headache, nausea, eye-watering, drowsiness, irritation of respiratory tract, irritation to eyes, spotted vision, convulsions, dilation of pupils.

Toxicity, skin absorbtion: Denatured alcohol can also easily be absorbed through the skin, so protective gloves should always be worn. Rashes might develop if proper skin protection is not used. Protective gloves made of nitrile, butyl, PVC and latex will all work for alcohol.

Eye contact: Splash may cause redness, irritation.

Ingestion: Ingestion may be fatal or cause blindness in addition to the above mentioned symptoms.

Turpentine

Turpentine - or gum turpentine - is made from distilled pine resin. It is not the same as mineral turpentine or mineral spirit (white spirit or Stoddard solvent) which are all petroleum destillates. However - their uses are very similar.

Turpentine is used for thinning oil paints, enamels, varnish and oil based stains. And can also be used for cleaning brushes and equipment after use - as long as turpentine can be used as their solvent.

Flammability: Very flammable. Never work with turpentine in the presence of an open flame or hot surfaces.

Toxicity, inhalation: Inhalation (acute exposure) can cause dizziness, headache, nausea, eye-watering, irritation of respiratory tract, irritation to eyes, serious irritation to the kidney, unconsciousness. Repeated over exposure may cause severe health problems like memory loss, heart palpitation, kidney damage, central nervous system damage, mental confusion, coma, death.

Toxicity, skin absorbtion: Can be absorbed through skin, so protective gloves made of nitrile or butyl are recommended. Other glove materials are permeable.

Eye contact: Splash may cause redness, irritation.

Ingestion: Harmful or fatal. May cause nausea, vomiting, diarrhea and gastrointestinal irritation. Warning: If turpentine is ingested - DO NOT INDUCE VOMITING! - the chemical could spill over to the lungs and cause lung inflammation or pneumonia!

CAUTION: Rags soaked with turpentine can self ignite!

White Spirit, Mineral Spirit, Stoddard Solvent, Paint Thinner

These are all paraffin-derived petroleum destillate, used as paint thinners and solvents. Also used as a cleaning/degreasing agents and cutting fluids in the mechanical industry.

Flammability: Very flammable. Never work with mineral spirits in the presence of an open flame or hot surfaces. Avoid spreading on a large surface area as fire and health risks will increase dramatically! Always ensure adequate ventilation to avoid inhalation and reduce the risk of ignition.

Toxicity, inhalation: Inhalation may cause headache, dizziness, irritation or respiratory tract, eye irritiation, stupor, depression of the central nervous system, watering of eyes, weakness, nausea, muscle twitsches, kidney effects. If aspiration into lungs happen, this can cause pneumonia or death. Convulsions, unconsciousness and death are related to sever overexposure.

Toxicity, skin absorbtion:Skin irritation mostly. Can be absorbed through skin with symptoms similar to inhalation. Protective gloves made of nitrile are best. Avoid PVC and latex gloves - these are easily permeated by mineral spirit.

Eye contact: Splash may cause redness, irritation.

Ingestion: Harmful or fatal if swallowed, symtoms are nausea, weakness, muscle twitches, gastrointestinal irritation, diarrhea, unconsciousness, death. If mineral spirit is ingested - DO NOT INDUCE VOMITING! - the chemical could spill over to the lungs and cause lung inflammation or pneumonia!

CAUTION: Rags soaked with mineral spirit can self ignite!

Odorless mineral spirit

This is mineral spirit that have been utterly refined to remove some of the toxic aromatic compounds. It still has an odor, but it is less pronounced than white spirit or mineral spirit. Same uses as mineral spirit.

Toxicity, inhalation: Acute exposure from inhalation may have the following symptoms: Headaches, dizziness, weakness, eye watering, nausea, irritation of the respiratory tract, muscle twitches. Can also have an effect on kidneys.

Toxicity, skin absorbtion: Can be absorbed through skin with symptoms similar to inhalation. Protective gloves made of nitrile are best. Avoid PVC and latex gloves.

Eye contact: Splash may cause redness, irritation.

CAUTION: Rags soaked with mineral spirit can self ignite!

Japan Drier

This is an oil drying agent (accelerator) that can be added to oil based paint and finishes to speed up the drying and hardening. Should not be used with synthetic finishes. Contains several drying agents as organo-metallic compounds and metal salts (e.g. zirconium 2-ethylhexanoate, cobalt napthenate, napthenic acid manganese salt - amounts depend upon the manufacturer) in mineral spirit (Stoddard Solvent).

Flammability: Very flammable. Same hazards as mineral spirit.

Toxicity, skin absorbtion: Skin irritation, redness, burning, drying and cracking. Can be absorbed through skin with symptoms similar to inhalation. Protective gloves made of neoprene are best.

Eye contact: Eye irritant. Vapors or splash may also cause redness, stinging, tearing, irritation.

CAUTION: Rags soaked with Japan Drier can self ignite!

M.E.K - Methyl Ethyl Ketone

Also called butanone. Its main use is as a solvent and thinner for lacquer, varnishes, cellulose acetate, nitrocellulose coatings and synthetic finishes. It has a slower evaporation rate than acetone. It can soften and damage PVC as well as other plastic materials.

MEK is also used as a denaturing agent in denatured alcohol.

Flammability: Extremely flammable. Never work with MEK in the presence of an open flame or hot surfaces. If the vapor concentration is high enough, a spark (e.g. from static electricity) can cause explosion.

Toxicity, inhalation: Inhalation (acute exposure) may cause dizziness, headache, drowsiness, nausea, watering of eyes, numbness in fingers, arms, legs. Prolonged exposure can cause irreversible neurological and physiological damage.

Toxicity, skin absorbtion: MEK is readily absorbed through skin. Butyl is the only material that gives adequate protection. MEK permeates latex, nitrile, neoprene and may dissolve PVC. Skin absorption produces similar effects as for inhalation. May also cause drying of skin, numbness in fingers, arms.

Eye contact: Eye irritant. Vapors or splash may also cause redness, stinging, burns, tearing, excessive swelling.

Ingestion: Harmful. May cause irritation of mouth, throat, stomach, headache, dizziness, nausea.

Toluene

Also called methylbenzene. Used as a paint thinner and stripper for paint, lacquer.

Flammability: Extremely flammable. Never work with toluene in the presence of an open flame or hot surfaces. If the vapor concentration is high enough, a spark (e.g. from static electricity) can cause explosion.

Toxicity, inhalation: Vapor is very harmful and may cause dizziness, headache, fatigue, hallucinations, watering of eyes, color vision loss, anesthesia, irregular heartbeat, death. Long term effects includes memory loss, kidney and liver damage, neurological and physiological damage.

Toxicity, skin absorbtion: Besides being a skin irritant and a cause of dermatitis, it can also be absorbed through the skin. Symptoms include numbness - and in severe cases the same symptoms as from inhalation. For protection, use viton gloves.

Eye contact: Eye irritant. Vapors or splash may also cause redness, stinging, burns, tearing, excessive swelling.

Ingestion: Harmful or fatal. May cause headache, nausea and vomiting, loss of coordination, burning sensation and irritation in mouth and stomach, diarrhea, coma.

VM&P Naphtha

Varnish Makers and Painters' Naphtha - used as a thinner for certain paints and varnishes.

Flammability: Extremely flammable. Never work with VM&P Naphtha in the presence of an open flame or hot surfaces. If the vapor concentration is high enough, a spark (e.g. from static electricity) can cause explosion.

Toxicity, inhalation: Vapor is harmful - and inhalation may cause symptoms like dizziness, headache, drowsiness, eye watering, irritation of respiratory tract, weakness, drowsiness. Severe exposure may cause unconsciousness, anesthesia, irregular heartbeat, death.

Toxicity, skin absorbtion: It is a skin irritant that also can cause dermatitis, drying of skin. It is also absorbed through the skin. Symptoms includes numbness in fingers and arms and in severe cases - same symptoms as for inhalation. Gloves made of nitrile are the best and the recommended protection.

Eye contact: Eye irritant. Vapors or splash may also cause redness, stinging, tearing, excessive swelling.

Ingestion: Harmful or fatal if swallowed. May cause nausea and vomiting, diarrhea, gastrointestinal irritation.

How to safely dispose of shop chemicals?

Whatever shop chemical you want to get rid of - never dump it in the drain! It is illegal to dump solvents and finishes in the drain in many states, and you could also cause an explosion and damage to the sewer system if you are unlucky... The same goes for dumping it in the regular trash (illegal and also a fire hazard). You are however allowed to put empty, dry containers in the regular trash.

To help us dispose of these substances safely and legally, many cities and counties have "Household Hazardous Drop-Off Facilities" where you can bring your hazardous waste. You can give your city/county a call - or go online - to get their guidelines.

If you have several different finishes/solvents you want to dispose of - DO NOT MIX THEM TOGETHER! Some mixes might be dangerous! And the "Household Hazardous Drop-Off Facilities" might not take your mixture, or you might have to pay for it.