Advertisement
Formaldehyde—which is colorless and has a characteristic
pungent, irritating odor—is ubiquitous. It is produced by the
oxidation or combustion of methane and other carbon
compounds and is therefore present in forest fires,
automobile exhaust, and tobacco smoke. When produced in
the atmosphere by the action of sunlight and oxygen on
atmospheric methane and other hydrocarbons, formaldehyde
becomes part of smog.
The primary exposure concern is for the workers in the
industries producing or using formaldehyde. Including indirect
employment, over 4 million people work in the formaldehyde
industry across approximately 11,900 plants in the U.S. and
Canada alone. For example, the textile industry uses
formaldehyde-based resins as finishers to make fabrics
crease-resistant. Formaldehyde-based materials are key to
the manufacture of automobile transmissions, electrical
systems, engine blocks, door panels, axles and brake shoes.
Occupational exposure to formaldehyde by inhalation is
mainly from three types of sources: thermal or chemical
decomposition of formaldehyde-based resins, formaldehyde
emission from aqueous solutions (for example, embalming
fluids), and combustion of a variety of organic compounds.
Because formaldehyde resins are used in many construction
materials it is one of the more common indoor air pollutants.
At concentrations above 0.1 ppm in air, formaldehyde can
irritate the eyes and mucous membranes, resulting in watery
eyes. Formaldehyde inhaled at this concentration may cause
headaches, a burning sensation in the throat and difficulty
breathing, and can trigger or aggravate asthma symptoms.
When treated with phenol, urea, or melamine, formaldehyde
produces polymer resins that are commonly used as
permanent adhesives in plywood and carpeting, in nail
3
Advertisement
