Formaldehyde
Sensory irritation has also been reported at lower levels, but is then
difficult to distinguish from background. Most studies show no effect on lung function in either
asthmatics or non-asthmatics. Formaldehyde causes skin irritation and has corrosive properties when
ingested. In some sensitized individuals, contact dermatitis may occur at challenge concentrations as
low as 30 ppm.
Formaldehyde as a gas is highly reactive and is absorbed quickly at the point of contact. It is rapidly
metabolised and is also produced by endogenous metabolism. Exposure to high concentrations (up
to 15 ppm in rats) does not result in increased blood concentrations. Repeated formaldehyde
exposure caused toxic effects only in the tissues of direct contact after inhalation, oral or dermal
exposure characterised by local cytotoxic destruction and subsequent repair of the damage. The
typical locations of lesions in experimental animals were the nose after inhalation, the stomach after
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