Wood Toxicity: Symptoms, Species, and Solutions
by Andi Wolfe
Ohio State University, Department of Evolution, Ecology, and Organismal Biology
Tens of thousands of tree species from hundreds of plant families grow in nearly all habitats. Only a small number of those species are used for construction, paper production, furniture, and wood turning. Wood turners select woods based on their grain, figure, and color; their workability; and their availability.
Wood is considered a friendly material that is easy to work, easy to find or purchase, and beautiful in turned objects. However, some species of trees produce secondary compounds that can cause health problems or temporary discomfort, and all wood dusts can cause health problems.
You may have a reaction to any wood that you use, or you may go a lifetime without any problems whatsoever. In addition, you may have used a wood known to cause a reaction with no problems for years, but then one day have a severe reaction to what you thought was a “safe” wood.
The most common symptom of wood toxicity is irritation of the skin or mucous membranes. However, there are many other symptoms, including: allergic contact dermatitis, hives, coughing, nose bleeds, runny nose, asthma, pneumonitis or bronchitis, sore throat, dizziness, nausea, vomiting, blisters, septic wounds (from splinters), and pink eye.
Direct contact with secondary compounds in wood dust causes irritation of the skin, eyes, nose, throat, and lungs. Irritation may be more severe in hot and humid environments, or if you are sweating. The pH of skin is slightly acidic, and may cause a chemical compound to change from something that is not irritating to one that is problematic – this is more severe if sweat is present. Wood dust can accumulate under watchbands, at the waist band of clothing, under collars, in arm pits, in socks and shoes, and any article of clothing that forms a convenient collecting place. Wood dust is also easily inhaled while working with wood, and dust that accumulates in the shop can cause problems after you have finished turning.
Higher levels of toxicity reactions include allergic contact dermatitis, asthma, or both. More severe health problems include anaphylactic shock, issues with the lungs, or systemic reaction involving the entire body. Reactions beyond direct irritation usually resolve only after medical diagnosis and treatment.
Although any species of wood has the potential to cause a reaction in any particular individual, several families of plants have compounds known to cause irritation or allergic reactions, and many species of the same genus have identical or similar compounds that can cause a reaction. Many chemical compounds from distantly related species may be similar enough to cause a reaction, too. Thus, if you become allergic to a chemical in rosewood, for example, you may also have a sensitivity to a chemical in another species containing a different secondary compound.
Knowing the botanical identity of the tree is important when purchasing woods known to cause allergic reactions. However, this is not a trivial task. Tradenames of woods may refer to more than one species, and tracking the source of a wood may be impossible by the time it has passed through many hands from forest to vendor. For example, wood blanks labeled as “rosewood” may come from several different species of Dalbergia, or may come from Machaerium scleroxylon, Metopium brownie, and several different species of Gluta, Melannorrhoea, and Swartzia. These belong to different and unrelated families, and the types of reactivity are different. Similar challenges in identification can be found for wood blanks known for wood toxicity labeled as ash, blackwood, ebony, mahogany, maple, mesquite, padauk, redwood, teak, and walnut.
Best practices for shop safety include the using a dust mask or respirator, removing dust at the source, and protecting your skin from exposure to wood dust. A barrier cream that’s sweat-resistant, such as 3M Cavilon, Brave Soldier Friction Zone, or pr88 may protect exposed skin. Wearing tight-fitting long sleeves, a turning smock, closed-toe shoes, long pants, a hat or headscarf can also help. It’s also good practice to wash your hands before you eat or use the bathroom (allergic contact dermatitis of certain areas of the body would be extremely uncomfortable). You can help prevent problems with sensitization if you wash your clothes and shower after you have worked with toxic dust. Other members of a household may be affected if you track dust into the house into shared spaces, so keep the shop free of dust.
Direct irritation of skin or mucous membranes usually clears up in a matter of hours. If it persists more than a day, you may have been sensitized to secondary compounds. You can treat minor irritation with the same over-the-counter remedies used for poison ivy. Allergic reactions need prompt medical attention, and may include treatment with steroids. Allergy testing to specific wood dusts can isolate the species that are causing problems, but it is important to identify the wood to exact species. This can be done by sending a sample of the wood to a lab such as the USDA Forest Products Laboratory (https://www.fpl.fs.fed.us/research/centers/woodanatomy/wood_idfactsheet.php).
Tables 1 – 3 list species of trees commonly used by wood turners that are known for wood toxicity. Reported symptoms are also listed. Table 1 is organized by common name, Table 2 by botanical name, and Table 3 includes the species known for the most severe reactivity. There may be species not on this list that cause problems for turners, but they have not yet been reported in the medical literature.
A helpful online resource that includes information about economically important timbers is the Wood Database (http://www.wood-database.com). A good reference book about wood toxicity is “Woods Injurious to Human Health – A Manual” by Björn Hausen (1981) ISBN 3-11-008485-6.
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