Immediately Dangerous to Life or Health Concentrations (IDLH)
CAS number: 50–00–0
NIOSH REL: 0.016 ppm TWA, 0.1 ppm 15-minute CEILING; NIOSH considers formaldehyde to be a potential occupational carcinogen as defined by the OSHA carcinogen policy [29 CFR 1990].
Current OSHA PEL: 0.75 ppm TWA, 2 ppm STEL
1989 OSHA PEL: Same as current PEL
1993-1994 ACGIH TLV: 0.3 ppm (0.37 mg/m3) CEILING, A2
Description of Substance: Nearly colorless gas with a pungent, suffocating odor.
LEL: . . 7.0% (10% LEL, 7,000 ppm)
Original (SCP) IDLH: 30 ppm
Basis for original (SCP) IDLH: Patty  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 1936-1960].” Because Patty  also reported that “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 in man [Kodak 1936-1960],” 30 ppm seems reasonable as the IDLH.
Short-term exposure guidelines: None developed
ACUTE TOXICITY DATA
Lethal concentration data:
|Species||Reference||LC50(ppm)||LCLo(ppm)||Time||Adjusted 0.5-hrLC (CF)||Derivedvalue|
|Izmerov et al. 1982Izmerov et al. 1982
|2 hr2 hr
|533 ppm (1.6)533 ppm (1.6)
815 ppm (1.0)
|53 ppm53 ppm
Other animal data: RD50 (mouse), 3.13 ppm [Alarie 1981].
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 1936-1960]. 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].
|Revised IDLH: 20 ppmBasis for revised IDLH: The revised IDLH for formaldehyde is 20 ppm based on acute inhalation toxicity data in humans [IARC 1982; Kodak 1936-1960; NRC 1981]. [Note: NIOSH recommends as part of its carcinogen policy that the “most protective” respirators be worn for formaldehyde at concentrations above 0.016 ppm. OSHA currently requires in 29 CFR 1910.1048 that workers be provided with and required to wear and use the “most protective” respirators in concentrations exceeding 75 ppm (i.e., 100 × the OSHA PEL of 0.75 ppm).]|
1. Alarie Y . Dose-response analysis in animal studies: prediction of human responses. Environ Health Perspect 42:9-13.
2. IARC . IARC monographs on the evaluation of the carcinogenic risk of chemicals to humans. Vol. 29. Some industrial chemicals and dyestuffs. Lyon, France: International Agency for Research on Cancer, pp. 345-389.
3. Izmerov NF, Sanotsky IV, Sidorov KK . Toxicometric parameters of industrial toxic chemicals under single exposure. Moscow, Russia: Centre of International Projects, GKNT, p. 69.
4. Kodak [1936-1960]. Personal observations. Rochester, NY: Eastman Kodak Company, Laboratory of Industrial Medicine. [From Patty FA, ed. . Industrial hygiene and toxicology. 2nd rev. ed. Vol. II. Toxicology. New York, NY: Interscience Publishers, Inc., p. 1971.]
5. NRC . Health effects of formaldehyde. In: Formaldehyde and other aldehydes. Chapter 7. Washington, DC: National Academy Press, National Research Council, National Academy of Sciences, Committee on Aldehydes, Board on Toxicology and Environmental Health Hazards.
6. Patty FA, ed. . Industrial hygiene and toxicology. 2nd rev. ed. Vol. II. Toxicology. New York, NY: Interscience Publishers, Inc., p. 1971.
7. Skog E . A toxicological investigation of lower aliphatic aldehydes. I. Toxicity of formaldehyde, acetaldehyde, propionaldehyde and butyraldehyde; as well as acrolein and crotonaldehyde. Acta Pharmacol Toxicol 6(4):299-318.