What is formaldehyde?
Formaldehyde is a colourless, flammable gas with a pungent/strong odour. Water-based solutions containing dissolved formaldehyde, known as 'formalin', are used in many environments, including:
- forensic/hospital mortuaries and pathology laboratories
- funeral (embalming) industry
- resins manufacture
- leather and fur tanning
- photographic film processing
- sanitising treatments
- analytical laboratories
Resins manufactured with formalin are used in:
- pressed wood manufacture (including MPB - manufactured particleboard; MDF - medium density fibreboard; and laminated surfaces)
- paper and textile treatments
- fibreglass industry
- foam insulation
- foundry industry
- firelighter manufacture
- anti-graffiti wall sealer
The major use of formalin is in adhesives used in the manufacture of resins used to make pressed wood products, particularly particleboard and MDF. Another major use is in medicine-related laboratories where it is used to fix tissues and organs, and in the funeral industry, in embalming processes, where it is a disinfectant and preservative. This is also a use in some museums. Formaldehyde used as a preservative in personal care and consumer products - at low concentrations (eg nail products).
Formaldehyde is naturally produced during burning of organic matter and by a variety of natural biological and chemical processes. It is present in vehicle emissions. It is also in cigarette smoke, and is emitted from cooking and heating appliances such as gas stoves and heaters.
Formaldehyde is toxic by inhalation, by skin contact, and by swallowing. It is a recognised carcinogen.
- Carcinogenic: In 2004 the International Agency for Research on Cancer (IARC) classified formaldehyde as a Group 1 carcinogen, that is, it is carcinogenic to humans (there is sufficient evidence it can cause nasopharynx - nasal cancers; and strong evidence it causes leukaemia and increases the risks of other cancers). In fact, a recent (August 2014) US National Academies of Science (NAS) assessment of the cancer risks from formaldehyde has confirmed it poses a threat to humans for three types of cancer: nasopharyngeal cancer; sinonasal cancer; and myeloid leukaemia.*
- Potential Reproductive effects: There has been some evidence that working with formaldehyde may increase a woman's chances of having fertility problems or a miscarriage. Most work exposures to formaldehyde are unlikely to be high enough to enter breast milk (but this is based on US advice, where the exposure standard is much lower). However formaldehyde may enter breast milk at exposure levels that are found in some workplaces, such as anatomy and mortuary science laboratories. Check this page on the NIOSH website for more information.
- Sensory irritant: Breathing formaldehyde vapour can result in irritation of nerves in the eyes and nose, which may cause burning, stinging or itching sensations, a sore throat, teary eyes, blocked sinuses, runny nose, and sneezing.
Contact irritant: Skin contact with formalin solution or paraformaldehyde can cause skin rashes and allergic skin reactions. For anyone who is allergic to formaldehyde, even very low concentrations are likely to cause skin reactions.
Splashes into the eyes can cause irritation, corrosion of the cornea, and potentially blindness.
Reactive: Formaldehyde is a highly reactive, flammable gas and can form explosive mixtures in air. It is fire hazard when exposed to flame or heat. Formaldehyde solutions can be flammable when formaldehyde or methanol concentrations in the solutions are high.
Formaldehyde is incompatible with many chemicals and can react, sometimes violently, with some chemicals, including strong oxidisers (e.g. bleach) and acids.
Workers at risk
Occupational exposure to formaldehyde occurs in a wide variety of occupations and industries.
- Short-term exposures to high levels have been reported for embalmers, pathologists and paper workers.
- Lower levels have usually been encountered during the manufacture of man-made vitreous fibres, abrasives and rubber and in formaldehyde production industries.
- A very wide range of exposure levels has been observed in the production of resins and plastic products. The development of resins that release less formaldehyde and improved ventilation has resulted in decreased exposure levels in many industrial settings in recent decades.
Workers potentially at risk of experiencing health effects include:
- embalmers, forensic/hospital mortuary workers, pathology laboratory workers,
- museum curators,
- formaldehyde resin manufacturers,
- workers who repack raw formaldehyde or use it in the formulation of other products, and
- users of formaldehyde resins.
Factors that can contribute to the greater risk of health effects in these industries are high concentrations of formaldehyde in the products that are handled; long exposure durations; high levels of manual handling of the products; and specific work processes such as weighing out, mixing in open tanks, cleaning and maintaining equipment, and heating and spraying products, which can generate vapour.
Occupational exposure standard
The current national occupational exposure standard for formaldehyde is 1 part per million (ppm) or 1.2 mg/m3 8-hour time-weighted average (TWA) and 2 ppm or 2.5 mg/m3 short-term exposure limit (STEL).
The NICNAS report recommends that the occupational exposure standard be lowered to 0.3 ppm 8-hour TWA and 0.6 ppm STEL.
The US standard is much lower than the Australian one. The Occupational Safety and Health Administration (OSHA) has set the permissible exposure limit (PEL) at 0.75 parts per million (ppm) as a time-weighted average (TWA), with a short-term exposure limit of 2 ppm. The NIOSH recommended exposure limit (REL) is 0.016 ppm (TWA), or 0.1 ppm (15-min ceiling).
The employer must implement the hierarchy of control - that is, begin with eliminating the use of formaldehyde if possible. If it is not 'reasonably practicable' to eliminate, then the employer must:
- Replace high concentration formalin products with low concentrations or less hazardous or formaldehyde-free products, wherever possible.
- Ensure there is an effective ventilation system in place, as this is a key control measure for reducing exposure to formaldehyde.
- Monitor the workplace to ensure the exposure levels are below the occupational exposure standard.
- Ensure that skin contact with formaldehyde solutions is avoided - this means implementing safe systems of work; providing appropriate PPE and the relevant training.
- Ensure that relevant Australian standards and/or guidance from manufacturers is followed in the selection and use of personal protective equipment. Respirators need to be provided where high formaldehyde levels and high frequency exposures may be encountered which may be above the occupational exposure standard.
- Ensure that the need to dilute formalin is avoided, by where possible buying products with concentrations of formaldehyde appropriate for the intended use.
- Ensure workers avoid spraying and brushing of formalin. Formaldehyde should be sprayed only where absolutely necessary and if both adequate engineering (e.g. local exhaust ventilation) and personal protective controls are in place.
- Review the (Material) Safety Data Sheet (M)SDS, labels and training materials to take into consideration the changes in the health hazard classification of formaldehyde.
- From IARC - 2006 Monograph Volume 88 (full report - note the monograph also covers two glycol ethers)
- NICNAS - note Australia's industrial chemicals notification/assessment body states that workplace levels are 'rarely' at hazardous levels. We do not agree. Nevertheless, NICNAS has the following information:
- Priority Existing Chemical (PEC) Report (no 68) [PDF document]
- NIOSH/CDC topic information page on Formaldehyde - with links to many more sites and factsheets.
- * National Academies of Science news release and report summary and full report on formaldehyde.
We wish to acknowledge as sources for this information the NICNAS and IARC websites.
Last amended September 2019