Methyl formate

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.