Agent Name


CAS Number




Major Category

Other Classes


Gas: Methanal; Methyl aldehyde; Methylene oxide; Aqueos: Formalin; [NIOSH] Formic aldehyde; Oxymethylene; [ACGIH]




Nearly colorless gas with a pungent, suffocating odor; Formalin is an aqueous solution that is 37% formaldehyde by weight; inhibited solutions contain 6-12 % methyl alcohol. [NIOSH] Sold as water solutions containing 37%, 44%, or 50% formaldehyde; [ACGIH]


Used in the production of formaldehyde resins, plywood, particle board, paper, and urea-formaldehyde foam; embalmers and laboratory workers may be exposed to levels above 1 ppm; [LaDou, p. 502-3] The major industrial consumers of formaldehyde resins are molded plastic parts, decorative laminates, photographic film, and plywood paneling. High formaldehyde exposures were documented in carpet installers and parquet tile fitters. Formaldehyde also exists as a polymer (paraformaldehyde) and as a trimer (sym-trioxane or trioxmethylene). [ACGIH] Occupational asthma reported in hospital workers; [Malo] Also at risk for asthma and allergic contact dermatitis are housekeeping personnel, machinists, and textile workers.


Liquid causes first degree burns on short exposure; [CHRIS] Inhalation of formaldehyde can produce bronchospasm and pulmonary edema. [ATSDR Medical Management] Skin sensitization reported from coolants, photographic chemicals, paper, carpets, and fabric resins. [Marks, p. 88] [Occupational asthma due to formaldehyde. Burge PS et al. Thorax 1985 Apr;40(4):255-60.] There is sufficient evidence that formaldehyde causes nasopharyngeal cancer and leukemia in humans. [IARC Monograph Volume 100F (2012): Formaldehyde] "Although the epidemiological studies are equivocal or insufficient to confirm an increased risk of cancer in formaldehyde-exposed workers, the studies do not exclude the possibility of a formaldehyde-related cancer risk." A survey of U.S. manufacturers of formaldehyde or formaldehyde resins showed decreasing worker exposure since the 1950s with an average of 1.00 to 1.15 ppm (1956 to 1967) down to 0.35 to 0.38 ppm (1980-1981). A study published in 1985 found mean exposures of 0.74 ppm (embalmers), 0.35 ppm (plywood manufacturers), 0.92 ppm (particle board manufacturers), 0.74 ppm (urea-formaldehyde foam manufacturers), and 0.42 ppm (urea-formaldehyde foam insulation installers). Formaldehyde causes eye irritation at 0.01-2.0 ppm, upper airway irritation at 0.10-25 ppm, lower airway and chronic pulmonary obstruction at 5-30 ppm, and pulmonary edema at 50-100 ppm. [ACGIH]


See 29CFR1910.1048 (Code of Federal Regulations)

Reference Link

OSHA Technical Links: Formaldehyde

Exposure Assessment
Skin Designation (ACGIH)


Ceiling (ACGIH)

0.3 ppm


0.75 mg/m3, STEL(OSHA) = 2 ppm


0.3 ppm

Excerpts from Documentation for IDLHs

Human data: It has been reported that exposure to 10 to 20 ppm produces almost immediate eye irritation and a sharp burning sensation of the nose and throat which may be associated with sneezing, difficulty in taking a deep breath, and coughing; recovery is prompt from these transient effects [Kodak 19361960]. It has been estimated that exposure for 5 to 10 minutes to 50 to 100 ppm might cause serious injury to the lower respiratory passages [Kodak 1936-1960]. The following exposure-effect data has also been reported: Most subjects experience irritation of the eyes, nose, and throat at 1 to 3 ppm; many subjects cannot tolerate prolonged exposures to 4 to 5 ppm; and difficulty in breathing was experienced at 10 to 20 ppm [IARC 1982]. In a summary of health effects data, upper airway irritation and increased nasal airway resistance were reported at 0.1 to 25 ppm and lower airway and chronic pulmonary obstruction at 5 to 30 ppm [NRC 1981].

Odor Threshold Low

0.02 ppm

Odor Threshold High

1.9 ppm


3 ppm

Lethal Concentration

LC50 (mice) = 454 mg/m3/4H

Explanatory Notes

Odor threshold from CHEMINFO; In HSDB: odor threshold = 0.5-1 ppm; another reference in HSDB gives odor threshold of 1.47 mg/m3 (1.2 ppm) to 73.5 mg/m3 (60 ppm); See "2016 Notice of Intended Changes." [TLVs and BEIs]

Half Life

Urine (for formic acid): 80-90 minutes; [TDR, p. 713]

Reference Link

ATSDR Medical Management - Formaldehyde

Flammability (NFPA)

4: Burns readily

Adverse Effects
Skin Sensitizer




Toxic Pneumonitis



Skin Burns

IARC Carcinogen

Known Carcinogen

NTP Carcinogen

Anticipated Human Carcinogen

ACGIH Carcinogen

Suspected Human

Links to Other NLM Databases
Health Studies

Human Health Effects from Hazardous Substances Data Bank:

Toxicity Information

Chemical Information

Search ChemIDplus

Biomedical References

Search PubMed

Related Information in HazMap

Occupational diseases associated with exposure to this agent:


Industrial Processes with risk of exposure:


Activities with risk of exposure: