by Professor Gene Wengert
Q.
What kinds of specific health problems are caused by wood dust? What steps should be taken in the workplace to avoid the hazards?
A.
Indeed, the previous comments I made and governmental control of wood dust both deal with wood dust as a carcinogenic material. But many people, including me, are severely allergic to dust. And the response varies by wood species. (Cedar dust is known to be a special carcinogenic problem.) Those species (especially tropical grown) with silica are known to create severe breathing problems. People with asthma should be especially careful. I myself get contact dermatitis from wood dust--quite a problem for a wood specialist! And of course, a little wood dust and some moisture can easily breed molds, which means another set of allergies!
The industrial cure for dust has taken a two-fold approach. First, is to eliminate it from the lungs by wearing an appropriate dust mask or other breathing apparatus. Note that these masks do not work on people with beards (etc.). The masks must be carefully fitted to avoid leaks. Also, note that the white colored fabric, elastic strap type nose/mouth masks that are widely available are oftentimes ineffective on wood dust--check the label for ones approved by NIOSH (a little more expensive, but so much more effective). The second control level is to control the dust--ventilate the area--suck the dust outside, preferably before the dust gets into the air. This is called an engineering solution. In the long run, OSHA requires that engineering solutions be used when economically practical, but personal protective devices are the short-term acceptable solution. Note that many filters (such as furnace filters) do not filter small enough particles to eliminate the wood dust risk--they get the large particles, but these particles aren't the problem in many cases.
As a word of caution, small or big companies are affected by the regulations. Plus, we all have a reasonable moral obligation to reduce exposure to wood dust. Monetary fines might be quite large for a violation. State enforcement of the federal standard is often the case. OSHA has been quite willing and is truly helpful in working with companies to control a problem if you go to them first. My prediction: Reductions in federal moneys will make this (wood dust) more of a state issue; federal paperwork is likely, but not much federal follow-up (compared to past activities).
In your specific case, try an exhaust fan to the outside whenever "he" is in the shop. Run it for ten minutes after he leaves too. Get a good dust vacuum system, including one for hand sanding--I use a big Powermatic collector (2 bag) that also hooks up to a sanding table. With a small exhaust fan, in addition, I can control the dust quite well.
One must realize that wood dust is both a political and medical issue. The brief history of wood dust is that in England a rare form of nasal cancer showed up in 2 studies (1965 and 1968) and the common denominator seemed to be furniture and cabinet workers, which was translated to wood dust. But the occurrence of the cancer was extremely small, so the study is somewhat questionable at best. Other European studies failed to show a connection. It is worth noting that England processed a large volume of tropical timbers.
In the late 1970s, the National Cancer Institute did a study and found 37 nasal cancers listed as the cause of death; 8 were furniture workers. In England, a follow-up study failed to find any workers who had nasal cancer, and who worked in a furniture factory after 1945.
What do we know about wood? There are several tropical species that have high silica content. This chemical often results in nasal irritation on many people. There are also many people allergic to dust, molds, and other chemicals in wood.
In the 70s and early 80s, several groups studied the cancer risk from dust. It was weak. Then in 1985, OSHA was prohibited from regulating wood dust under the "nuisance dust" standard. So, OSHA begins the process of regulating wood dust, with a standard in 1989 and a subsequent court ruling making it ineffective, and so it goes today.
The basis for OSHAs initial rules were: 1) the evidence of carcinogenicity of wood is inconclusive; 2) a maximum exposure of 5 milligrams per cubic meter is appropriate for the irritant effects of wood and worker comfort. There was some evidence that softwoods (esp. western red cedar) were worse than hardwoods. Other groups wanted 1 mg/cubic meter.
Hope this helps you decide whether you want to breath wood. I personally use a very good dust filter mask at all times.
Professor Gene Wengert is Extension Specialist in Wood Processing at the Department of Forestry, University of Wisconsin-Madison.
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