Molecular formula: CH2O
Characteristics: The gas is colourless and very pungent.
Occurrence: Formaldehyde is introduced into the environment through the industrial production, manipulation, and elimination of adhesive and synthetic resin. It derives from the incomplete combustion of fossil fuels or waste. Sources of formaldehyde in the home include some manufactured wood furniture, carpets, and toys, where it is used as an adhesive. The chemical and textile industries are the largest emitters.
Impact: Formaldehyde is capable of causing atopic dermatitis and other allergic reactions. Exposure to low levels produces irritation of the upper respiratory tract’s mucous membrane and conjunctiva, coughing, and burning eyes. Excessive tearing, swelling, and pneumonia develop at exposure to high concentrations. Formaldehyde is a carcinogenic and mutagenic substance.
Limit: The WHO recommends not exceeding a long-term concentration of 60 mg/m3.