<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML><HEAD>
<META http-equiv=Content-Type content="text/html; charset=US-ASCII">
<META content="MSHTML 6.00.2800.1479" name=GENERATOR></HEAD>
<BODY id=role_body style="FONT-SIZE: 10pt; COLOR: #000000; FONT-FAMILY: Arial"
bottomMargin=7 leftMargin=7 topMargin=7 rightMargin=7><FONT id=role_document
face=Arial color=#000000 size=2>
<DIV>The following is an extract of an OSHA study done at a Denver automotive
paint shop where urethane containing polyisocyanates is sprayed daily. The
study concluded the workers were protected at an adequate level (they wore
protective suits and were using a forced air breathing system). I'm not
advocating not using automotive polyurethanes, but if you're going to use them,
be aware of the dangers and take the precautions recommended by the paint
manufacturers. I used to spray Imron with great results, but am now
experimenting with other paints to eliminate the hazard.</DIV>
<DIV> </DIV>
<DIV>Mike Moritko</DIV>
<DIV> </DIV>
<DIV> </DIV>
<DIV>OSHA Report Extract: </DIV>
<DIV> </DIV>
<DIV>Probably the most debilitating health effects from workplace exposure to
diisocyanates are respiratory and dermal sensitization. Exposures can lead to
sensitization depending on the type of exposure, the exposure concentration, the
route of exposure, and individual susceptibility. Dermal sensitization can
result in such symptoms as rash, itching, hives, and swelling of the
extremities.<SUP>18,21</SUP> Respiratory sensitization from exposure to
diisocyanates results in the typical symptoms of asthma. Estimates of the
prevalence of diisocyanate-induced asthma in exposed worker populations vary
considerably; from 5% to 10% in diisocyanate production
facilities,<SUP>22,23</SUP> to 25% in polyurethane production
plants,<SUP>22,24</SUP> and 30% in polyurethane seatcover
operations.<SUP>25</SUP><BR><BR>A worker suspected of having
diisocyanate-induced sensitization will present with symptoms of traditional
acute airway obstruction; e.g., coughing, wheezing, shortness of breath,
tightness in the chest, nocturnal awakening, etc.<SUP>18,20</SUP> Upon first
exposure to diisocyanates, the worker may develop an asthmatic reaction
immediately or several hours after exposure, after the first months of exposure,
or after several years of exposure.<SUP>18,20,23,26,27</SUP> some evidence
exists which suggests that the onset of sensitization occurs after a mean
exposure interval of two years.<SUP>28</SUP> After sensitization, any exposure,
even to concentrations below any occupational exposure limit or standard, can
produce an asthmatic response which may be life threatening. This asthmatic
reaction may occur minutes after exposure (immediate), several hours after
exposure (late), or a combination of both immediate and late components after
exposure (dual).<SUP>20,26</SUP> The late asthmatic reaction is the most common
occurring in approximately 40% of diisocyanate-sensitized workers.<SUP>29</SUP>
Recurrent nocturnal asthma has been described in workers sensitized to TDI and
MDI.<SUP>30,31</SUP> An improvement in symptoms may be observed during periods
away from the work environment (weekends,
vacations).<SUP>18,20,26</SUP><BR><BR>The percentage of sensitized workers with
persistent symptoms of asthma after years of no exposure may be 50% or higher.
Studies have shown that workers with persistent asthma have a significantly
longer duration of symptoms prior to diagnosis, larger decrements in pulmonary
function, and a severe degree of nonspecific bronchial hyperactivity at
diagnosis.<SUP>26</SUP> These data suggest that prognosis is improved with early
diagnosis of diisocyanate-induced respiratory sensitization and early removal
from diisocyanate exposure. This emphasizes the need to minimize workplace
exposure concentrations, and for active medical surveillance of all workers
potentially exposed to diisocyanates.<BR></DIV></FONT></BODY></HTML>