Methyl formate
May 1994
Immediately Dangerous to Life or Health Concentrations (IDLH)
CAS number: 107–31–3
NIOSH REL: 100 ppm (250 mg/m3) TWA, 150 ppm (375 mg/m3) STEL
Current OSHA PEL: 100 ppm (250 mg/m3) TWA
1989 OSHA PEL: 100 ppm (250 mg/m3) TWA, 150 ppm (375 mg/m3) STEL
1993-1994 ACGIH TLV: 100 ppm (246 mg/m3) TWA, 150 ppm (368 mg/m3) STEL
Description of substance: Colorless liquid with a pleasant odor.
LEL: . . . 4.5% (10% LEL, 4,500 ppm)
Original (SCP) IDLH: 5,000 ppm
Basis for original (SCP) IDLH: The chosen IDLH is based on the
statement by ACGIH [1971] that 5,000 ppm was considered the maximum concentration guinea pigs could tolerate for 60 minutes without serious disturbances [Schrenk et al. 1936].
Short-term exposure guidelines: None developed
ACUTE TOXICITY DATA:
Lethal concentration data:
| Species | Reference | LC50 (ppm) | LCLo (ppm) | Time | Adjusted 0.5-hr LC (CF) |
Derived value |
| G. pig | Schrenk et al. 1936 | ----- | 50,000 | 20 min | 43,500 ppm (0.87) | 4,350 ppm |
Lethal dose data:
| Species | Reference | Route | LD50 (mg/kg) | LDLo (mg/kg) | Adjusted LD | Derived value |
| Rabbit | Munch 1972 | oral | 1,622 | ----- | 4,542 ppm | 454 ppm |
Other animal data: It has been stated that 5,000 ppm was considered the maximum concentration that guinea pigs could tolerate for 60 minutes without serious disturbances [Schrenk et al. 1936].
Human data: No adverse effects were found in humans after exposure to 1,500 ppm for 1 minute [Schrenk et al. 1936].
| Revised IDLH: 4,500 ppm Basis for revised IDLH: The revised IDLH for methyl formate is 4,500 ppm based on acute inhalation toxicity data in animals [Schrenk et al. 1936]. Also, this value is 10% of the lower explosive limit of 4.5%. |
REFERENCES:
1. ACGIH [1971]. Methyl formate. In: Documentation of the threshold limit values for substances in workroom air. 3rd ed. Cincinnati, OH: American Conference of Governmental Industrial Hygienists, pp. 165-166.
2. Munch JC [1972]. Aliphatic alcohols and alkyl esters: narcotic and lethal potencies to tadpoles and to rabbits. Ind Med Surg 41:31-33.
3. Schrenk HH, Yant WP, Chornyak J, Patty FA [1936]. Acute response of guinea pigs to vapors of some new commercial organic compounds. XIII. Methylformate. Public Health Rep 51:1329-1335.