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Formaldehyde,
It’s Not Only Found
in FEMA Trailers
B Y
MICHAEL
D. SHAW
Judging by the uproar
over the past
several months, you might think that formaldehyde is a toxic chemical
that exists mostly in trailers purchased by the U.S. Federal Emergency
Management Agency.
If nothing else, this current crisis will get people
thinking about indoor air quality. After all, no less an authority than
our own EPA states that: “In the last several years, a growing body of
scientific evidence has indicated that the air within homes and other
buildings can be more seriously polluted than the outdoor air in even
the largest and
most industrialized cities.
Other research indicates that people spend approximately
90 percent of their time indoors. Thus, for many people, the risks to
health may be greater due to exposure to air pollution indoors than
outdoors.”
Easy To Find
Look anywhere in your home or
workplace— at the wood products, paint, drapery, carpets, paper, and
insulation materials—to name just a few items. These familiar fixtures
of our daily lives all contain formaldehyde, a colorless, pungent
smelling gas that can cause numerous nasty health effects. Relatively
low concentrations of formaldehyde can cause searing eye irritation,
skin rashes, and a host of respiratory symptoms.
You’d think that we should just get
rid of this ubiquitous compound, classified as “carcinogenic to humans”
by The International Agency for Research on Cancer, but its potential
dangers are trumped by its great utility. It is part of the adhesive in
pressed wood products, a preservative in some paints, a coating in most
fabrics, a binder in insulation, and it adds wet strength to certain
paper goods.
Environments can become contaminated
with this chemical due to excessive moisture, natural outgassing from
the materials themselves, and overzealously sealed-up buildings—the
biggest single cause of indoor air quality problems. In practice, it
does not take much to create a potentially hazardous situation,
especially in modern workplaces with windows that don’t open.
Since, in theory at least, we can
increase ventilation, and watch out for excessive moisture, what, if
anything can be done to limit the outgassing of formaldehyde? In other
words, how can we control the source?
Dealing with the Source
Any formaldehyde-treated product will
tend to emit less gas with time. So, the initial good news is that the
problem will always decrease, even if we do nothing.
Experience has shown that the worst
offenders are typically manufactured wood products (including
particleboard and medium density fiberboard) and most types of carpet
padding. Any new delivery of such items should be accompanied by
enhanced ventilation, ideally running 24 x 7 for the first few weeks of
installation.
Since 1984, in accordance with 24 CFR
3280.308 [Manufactured Home Construction and Safety Standards], the
Department of Housing and Urban Development (HUD) has promulgated
regulations limiting formaldehyde emissions in plywood materials to no
more than 0.2 ppm (partsper- million) and in particleboard materials to
no more than 0.3 ppm, when installed in manufactured homes.
Experience has shown that these
levels, mixed in the general air of the manufactured home, will normally
keep emissions below 0.01 ppm.
Other standards include the
following:
• OSHA’s Permissible Exposure Limit
of 0.75 ppm (8-hour time-weighted average) and a short-term exposure
limit of 2 ppm for 15 minutes;
• NIOSH’s Recommended Exposure Limit
of 0.016 ppm (10-hour time-weighted average) and Ceiling Value of 0.1
ppm;
• ACGIH’s (American Conference of
Governmental Industrial Hygienists) Short-Term Exposure Limit of 0.3 ppm
as a 15 minute time-weighted average—no more than four times per 8-hour
shift.
Reaction and Overreaction
On April 11, 2008, FEMA announced
that all future temporary housing units purchased by the agency must
meet strict new procurement specifications, including a requirement that
formaldehyde emission levels must test below 0.016 ppb [16
parts-per-billion].
While this might look great to the
uninitiated, it is well to consider that data compiled in 2005 pegs the
median concentration of formaldehyde in human breath at 4.3 ppb.
Moreover, a February, 2008 paper notes that the instrument method used
in the earlier paper (proton transfer reaction mass spectrometry)
underestimates formaldehyde concentrations, due to its low proton
affinity, and adjusts this to 10 ppb.
Since this is the median, half the
population will be above this value, and could likely “contaminate” a
trailer to above the new FEMA value.
Finally, epidemiological data does
not come close to supporting the 16 ppb standard, but when there’s a
choice between politics and science, politics tends to win—even if it’s
the public that loses.
FSM
Michael D. Shaw
is
executive VP and director of marketing for Interscan Corp., a
manufacturer of toxic gas detection instrumentation-- including units
for formaldehyde-- and related software. Reach him at
mds1@gasdetection.com.
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