Agent Name
CAS Number
Major Category
Other Classes
Formaldehyde formula graphical representation
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] "Therefore, commercially available ducted grossing stations are recommended to control formaldehyde exposure during gross examination in anatomic pathology laboratories, while canopy hood and recirculating grossing stations should be avoided." [PMID 26861729] 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.] “In two of the three large industrial cohort studies positive associations were observed for leukaemia, which were somewhat stronger for myeloid leukaemia. . . . There is sufficient evidence in humans for the carcinogenicity of formaldehyde. Formaldehyde causes cancer of the nasopharynx and leukaemia. . . . The Working Group was not in full agreement on the evaluation of formaldehyde causing leukaemias in humans, with a small majority viewing the evidence as sufficient of carcinogenicity and the minority viewing the evidence as limited." [IARC Monograph Volume 100F (2012): Formaldehyde] “Some studies have linked heavy workplace exposure to formaldehyde with AML risk, but this link has not been seen in some other studies." [] “We find no clear evidence of an excess risk of leukemia or myeloid leukemia in any large, well-conducted study.” [PMID 22983399] “Our reanalysis of the data from the NCI cohort study of workers in the formaldehyde industries provides no support for the hypothesis that formaldehyde causes AML, the LHM [lymphohematopoietic malignancy] of greatest prior concern.” [PMID 26147546] “. . . the largest cohort study found a significant increase in deaths from nasopharyngeal cancer only in the subset of workers whose average exposure was greater than or equal to 1 ppm. The no-observed-adverse-effect level (NOAEL) for squamous cell nasal cancer in a rat inhalation study is 2 ppm." 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)
Biomedical References

Exposure Assessment

Skin Designation (ACGIH)
0.1 ppm
0.3 ppm
0.75 ppm, STEL(OSHA) = 2 ppm
0.3 ppm
20 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
0.027 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; Odor threshold estimated at less than 0.5 ppm; [ACGIH]
Half Life
Urine (for formic acid): 80-90 minutes; [TDR, p. 713]
burn readily
1 ppm
10 ppm
40 ppm

Adverse Effects

Skin Sensitizer
Toxic Pneumonitis
Skin burns
IARC Carcinogen
NTP Carcinogen
Human carcinogen
ACGIH Carcinogen
Confirmed Human

Diseases, Processes, and Activities Linked to This Agent