Formaldehyde is used in the manufacture of formaldehyde-based resins and plastics used in many industries, but mostly in the wood-products industry. Formaldehyde-based resins are also used as adhesives. Formaldehyde is also used in a number of industries including agriculture, the building industry (to water- and grease-proof concrete and plaster), medicine-based industries (forensics, hospitals and pathology laboratories), embalming fluid in funeral homes and crematoria, film processing, textile treatments, leather tanning and a wide range of personal care and consumer products.
Substance name: Formaldehyde
CASR number: 50-00-0
Molecular formula: CH2O
Synonyms: formalin, methylene oxide, methyl aldehyde, methanal, HCHO, formic aldehyde, oxomethane, formol, oxymethylene, morbicid, veracur, methylene glycol, formalin 40, BFV, fannoform, formalith, FYDE, HOCH, karsan, lysoform, superlysoform, methan 21, melamine-formaldehyde resin.
In pure form, formaldehyde is a gas but is often used in liquid form after diluting with water. It is a colourless highly flammable liquid or gas with a pungent odour that is detectable at 1 part per million (ppm). Formaldehyde mixes with water, acetone, benzene, diethyl ether, chloroform and ethanol.
Melting Point: -117°C
Boiling Point: -19.2°C
Formaldehyde reacts with strong oxidisers, alkalis and acids, phenols and urea. Poisonous gases are produced if formaldehyde catches fire. It is very reactive, combines with many substances and polymerises easily.
The National Pollutant Inventory (NPI) holds data for all sources of formaldehyde emissions in Australia.
Exposure to low levels of formaldehyde irritates the eyes, nose and throat, and can cause allergies affecting the skin and lungs. Higher exposure levels can cause throat spasms and a build up of fluid in the lungs, leading to death. Contact can also cause severe eye and skin burns, leading to permanent damage. These symptoms may appear hours after exposure, even if no pain is felt. Formaldehyde can cause an asthma-like respiratory allergy. Any further exposure can cause asthma attacks with shortness of breath, wheezing, cough and/or chest tightness. Repeated exposures may cause bronchitis, with coughing and shortness of breath.
In 2004, the National Occupational Health and Safety Commission classified formaldehyde as a potential carcinogen (when inhaled). A carcinogen is a chemical capable of causing cancer.
Entering the body
Formaldehyde can enter the body by inhaling fumes (from smog, cigarettes and other tobacco products, gas cookers and open fireplaces), contact with solutions containing formaldehyde, or by eating and drinking foods containing formaldehyde. Eating formaldehyde-tainted foods may have a different effect than inhaling formaldehyde vapours.
Formaldehyde concentrations indoors are generally higher than outdoor levels, due to the relatively low indoor ventilation rate. There is also a higher usage of products indoors, such as building materials, consumer products and fabrics that may emit formaldehyde, and from other potential sources of formaldehyde such as from combustion of gas used in cooking and refrigeration. Opening windows and using fans are the easiest ways to reduce formaldehyde levels in a house.
It is also possible to eat or drink products contaminated by, or containing, formaldehyde or to be exposed via skin contact through cosmetics or consumer products.
Workplace exposure standards
Safe Work Australia sets the workplace exposure standard for formaldehyde through the workplace exposure standards for airborne contaminants:
- Maximum eight hour time weighted average (TWA): 1 parts per million (1.2 mg/m3)
- Maximum short term exposure limit (STEL): 2 parts per million (2.5 mg/m3)
These standards are only appropriate for use in workplaces and are not limited to any specific industry or operation. Make sure you understand how to interpret the standards before you use them.
Drinking water guidelines
The Australian Drinking Water Guidelines include the following guidelines for acceptable water quality:
- Maximum of 0.5 milligrams per litre of water for health purposes
Formaldehyde dissolves easily in water, and eventually decomposes. In air, formaldehyde decomposes relatively quickly (within 24 hours) to form formic acid and carbon monoxide. Formaldehyde does not bioaccumulate in plants and animals.
Chronic effects in animals may include shortened lifespan, reproductive problems, lower fertility and changes in appearance or behaviour. Chronic effects can be seen a long time after first exposure to a toxic chemical. Formaldehyde has high chronic toxicity to aquatic life. Formaldehyde may cause cancer and other chronic illnesses in rodents. Birds and terrestrial animals exposed to formaldehyde could contract similar diseases. Insufficient data are available to evaluate or predict the long-term effects of formaldehyde in plants.
Entering the environment
Formaldehyde is transported in air, water and contaminated soils.
Where it ends up
Formaldehyde is slightly persistent in water, with a half-life of 2-20 days. About 99% of emitted formaldehyde will eventually end up in the air, and the rest will end up in the water. Formaldehyde can also be formed as a result of photochemical reactions between other chemicals in already polluted air. These reactions may account for most of the formaldehyde in the air in some areas.
Currently (January 2007), there are no environmental guidelines for formaldehyde. In its 2006 evaluation of formaldehyde, the National Industrial Chemicals Notification and Assessment Scheme (NICNAS) recommended an ambient air standard in the order or 80 parts per billion.
The major industrial sources include manufacturing plants that produce or use formaldehyde, or substances that contain formaldehyde. Mining, wood and paper industries and electricity supply are those that produce the most formaldehyde. Catalytic cracking, coking operations and fuel combustion sources such as boilers, furnaces and engines in manufacturing processes also generate formaldehyde. Formaldehyde is present in urea-formaldehyde and phenol-formaldehyde resins and copper plating solutions.
Diffuse sources, and industry sources included in diffuse emissions data
Formaldehyde is released from burning fuel in homes, and is in products such as carpets and pressed wood products. It is directly emitted into the atmosphere and can also be formed in the atmosphere as a result of the photochemical oxidation of reactive organic gases in polluted atmospheres containing ozone and nitrogen oxides.
Formaldehyde can form as a result of forest fires, and is also present in animal wastes and the microbial products of biological systems. It can also be formed in seawater by photochemical processes.
Vehicle exhaust is a major source of formaldehyde.
Formaldehyde may be present in glues, fibreboard, particle board, furniture, textiles and some insulation. Formaldehyde-based resins are used in pressed wood, permanent press fabrics (clothing, manchester, draperies), wallpaper, paint, grocery bags and waxed paper. Detergents, cosmetics and other domestic chemicals (shampoos, hair conditioners and bubble baths) contain formaldehyde as an antimicrobial agent. Cigarettes, cigars and other tobacco products also contain formaldehyde.
Sources used in preparing this information
- Agency for Toxic Substances and Disease Registry, ToxFAQS: Formaldehyde, accessed January 2007.
- California Environmental Protection Agency (Cal/EPA) Air Resources Board Toxic Air Contaminant Summary: Formaldehyde, accessed January 2007.
- Environment Writer Chemical Backgrounder, accessed January 2007.
- Merck and Co. 2001, Merck Index, 13th Edition, USA.
- National Industrial Chemicals Notification and Assessment Scheme (NICNAS), 2006, 'Formaldehyde. Priority Existing Chemical Assessment Report No 28', November 2006.
- Technical Advisory Panel 1999, Final Report to the National Environment Protection Council.
- US Environment Protection Agency, Integrated Risk Information System (IRIS): Formaldehyde, accessed January 2007.
- Safe Work Australia, Workplace exposure standards for airborne contaminants, accessed October 2018.
- National Health and Medical Research Council (NHMRC), Australian Drinking Water Guidelines (2011) - Updated October 2017, accessed May 2018