Formaldehyde is a colourless, highly flammable, pungent smelling gas that enters the environment from man-made sources (for example, manufacturing industries) and natural sources including bush fires.
Formaldehyde is even produced in very small, non-harmful amounts by our bodies.
Formaldehyde in the environment
Formaldehyde does not persist for long in the environment. When it is present in air, most of it degrades to molecular hydrogen and carbon monoxide. When formaldehyde is present in water, it is rapidly converted to glycol. Formaldehyde is not commonly found in soil although it has been measured in soils around manufacturing plants where phenol/formaldehyde resins are used.
Uses of formaldehyde
Food and water
Formaldehyde occurs naturally in a variety of foods, including some fruits, fish, processed foods and alcoholic beverages. The Australian Drinking Water Guidelines set a health-based limit for formaldehyde of 0.5 mg/L for potable (drinking) water.
Formaldehyde and its derivatives are present in a wide range of consumer products where it is used as a preservative to protect from bacteria and mould spoilage. Types of products include:
- household cleaning agents
- dishwashing liquids
- fabric softeners
- shoe care products
- car shampoos and waxes
- carpet cleaning products
Formaldehyde is also present in smoke resulting from the combustion of tobacco products and wood fires.
Formaldehyde has been used in the cosmetic industry as a:
- preservative in products such as hair products, lotions, makeup and mouth washes
- hardener in nail treatments
Formaldehyde can be an ingredient in:
- hand cream
- bath products
- mascara and eye makeup
- mouth wash
- cuticle softeners
- nail creams
- vaginal deodorants
- shaving cream.
- sanitisers for equipment. (called formalin)
Clothing and fabrics
Formaldehyde-releasing chemicals are used as flame-retardants and to provide crease resistance in textiles and as a binder in textile printing. Durable-press or permanent-press resins containing formaldehyde have been used in cotton and cotton-polyester fabrics since the mid-1920s to minimise wrinkles during wear and laundering. Manchester and clothing that contains formaldehyde releasing chemicals can give off moderate amounts of formaldehyde into the air which can be more noticeable when the packaging is initially removed from new items. Formaldehyde may also be breathed in when wearing new clothes that release the gas.
Formaldehyde released from building materials has long been recognised as a significant cause of elevated formaldehyde levels that are frequently measured indoors. Pressed wood products (for example particleboard, medium density fibreboard and hardwood plywood) are considered to be the major sources of formaldehyde in homes. Formaldehyde release from carpets, carpet backings, vinyl floors, wall coverings and some insulation products has also been reported, with higher exposures being more likely in newly built or furnished homes.
Formaldehyde is also produced when using open fireplaces and un-flued gas or kerosene heaters.
The largest man-made source of formaldehyde in the environment is the combustion of fuel and therefore it is found in the air we breathe every day that is polluted by motor vehicle exhausts.
Although formaldehyde is not present in petrol, it is produced by incomplete combustion which occurs in internal combustion engines. The amount of formaldehyde generated depends on the composition of the fuel, the type of engine, the emission control applied, and the age and state of repair of the vehicle.
Formaldehyde is produced from many industrial activities and will be present in the air due to emissions from various industrial sites.
Formaldehyde is water soluble and rapidly metabolised in the body when you breathe, drink or eat it. Very small amounts may also be absorbed through your skin. Health effects caused by exposure primarily involve the body organs that first come into contact with formaldehyde for instance eyes, lungs, mouth, and skin.
Workers exposed to formaldehyde (for example clothing or furniture manufacturers and laboratory workers) will be exposed to higher levels of formaldehyde than the general population.
Symptoms of formaldehyde exposure
High level exposure
The major toxic effects caused by acute formaldehyde exposure by inhalation are eye, nose and throat irritation and effects on the nasal cavity. Other effects seen from exposure to high levels of formaldehyde in humans are coughing, wheezing, chest pains and bronchitis.
Lower level exposure
Formaldehyde, at levels commonly present in consumer goods, can be irritating to the eyes, nose, throat and the lungs. These sensory irritations are commonly described as itchy, sore or burning sensations. At concentrations higher than those associated with sensory irritation, formaldehyde may contribute to small, reversible effects on lung function.
Some people are more sensitive to formaldehyde effects than others. For the general population, skin exposure to formaldehyde solutions with concentrations of around 1 to 2% is likely to irritate skin. However, hypersensitive people can develop contact dermatitis after exposure to concentrations of formaldehyde as low as 0.003%.
There is no evidence to suggest that formaldehyde causes birth defects in humans or that formaldehyde absorbed by the mother can be transferred to the baby across the placenta or in breast milk.
Low levels of exposure for long periods of time
Studies in workers exposed to formaldehyde in the air found more cancer cases than expected. Based on human and animal studies, international authorities have determined there is enough evidence to suggest that in high enough doses and with long periods of exposure (many years) formaldehyde is carcinogenic (cancer-causing) to humans.
As exposures can occur from many sources in our everyday life, every effort should be made where possible to minimise any unnecessary exposure to formaldehyde for you and your family to reduce risk of health effects and becoming hypersensitive.
Reducing your exposure
Try these simple tips to reduce your levels of exposure to formaldehyde:
- Ensure you have adequate ventilation when using formaldehyde-containing products. Opening a door or window can lower formaldehyde levels in the home.
- Avoid or minimise exposure to cigarette smoke especially by not smoking indoors.
- Avoid using un-flued gas or kerosene heaters indoors.
- Minimise the number of formaldehyde-containing consumer and cosmetic products used in the home
- Wash new clothes prior to wearing and wash/air new toys and other products before use. Particularly if you can smell an odour.
For more information on formaldehyde contact SA Health’s Scientific Services on DLHealthPublicHealthServices@sa.gov.au.