The toxicology-based recommended exposure limits for
hardwood and softwood dust in working environments
have been derived identically, bearing in mind that hardwood
dust is a proven and softwood dust is a suspected
carcinogen.
Several organizations have set standards or given recommendations
for wood dust exposure (see Table 1).
These include Occupational Safety and Health Administration
(OSHA), National Institute for Occupational Safety
and Health (NIOSH), and American Conference of Governmental
Industrial Hygienists (ACGIH).
In Table 2, the most frequently found species of both
hardwood and softwood trees with their common and scientific
names are summarized.
While it is very simple to distinguish the wood by
morphological evaluations, the wood dusts produced in
working activities do not allow easy differentiation.
On the other hand, the possibility to distinguish the
relative percent contribution in dusts of hardwood and
softwood in exposed workers could help the evaluation of
toxicology-based occupational exposure limits.