Formaldehyde is used in many products. The gas has a distinctive smell at moderate concentrations and acts as a disinfectant when used in fumigation. Formalin (the gas dissolved in water) is widely used as a disinfectant and preservative, including for corpses. Half of all formaldehyde is made into urea-formaldehyde and phenol-formaldehyde resins. These resins are used as laminating agents in plywood and particle boards including medium-density fibreboard (MDF), as foam plastic in upholstery and as 'urea foam' insulation in walls and ceilings (see also Insulation materials ). They are often used as a finish for carpets, textiles and paper and make permanent-press clothes shrink-proof, crush-proof and crease-proof. It is also emitted as a result of industrial processes.
Formaldehyde is also used as a preservative in cosmetics, shampoos, nail-hardening solutions, veterinary treatments and as a soil steriliser. However, its use in cosmetics is declining, mainly because of the skin problems it causes and its use for this purpose is restricted in several countries.
The NHMRC has set a goal of a maximum of 0.1 ppm for formaldehyde in indoor air. In March 2002 it was announced that NICNAS would be conducting a review of formaldehyde to assess the risks for public health and the environment.
Formaldehyde is the most common air pollutant in houses and frequently contributes to allergic reactions. Small amounts of formaldehyde gas escape slowly from all formaldehyde products, in particular upholstery, foam insulation, laminated wood and particle board furniture, and permanent-press fabrics. At moderate concentrations, the gas causes sore and watery eyes, nose irritation and inflammation. At high concentrations, or with repeated exposure, formaldehyde causes headaches and chronic respiratory complaints similar to the common cold. In susceptible individuals, it has also been known to cause nausea, allergies and dermatitis. It causes cancer in animals and is a probable human carcinogen. The solution is poisonous if swallowed (see Poisons Information in Introduction).
As a gas, formaldehyde does not persist in the environment. The liquid quickly evaporates and decomposes in sunlight.
See also Insulating materials .
To avoid dangerous levels of formaldehyde indoors:
- avoid the use of particle boards and plywood
- if you do use particle boards and plywood, then seal with low-emission paint or varnish
- ensure there is adequate permanent ventilation particularly in cars and new houses
- avoid urea formaldehyde (UF) and tripolymer foam (a type of UF foam) as insulating materials and upholstery.