Methyl acetate

May 1994
Immediately Dangerous to Life or Health Concentrations (IDLH)

CAS number: 79–20–9

NIOSH REL: 200 ppm (610 mg/m3) TWA, 250 ppm (760 mg/m3) STEL

Current OSHA PEL: 200 ppm (610 mg/m3) TWA

1989 OSHA PEL: 200 ppm (610 mg/m3) TWA, 250 ppm (760 mg/m3) STEL

1993-1994 ACGIH TLV: 200 ppm (606 mg/m3) TWA, 250 ppm (757 mg/m3) STEL

Description of substance: Colorless liquid with a fragrant, fruity odor.

LEL:. . 3.1% (10% LEL, 3,100 ppm)

Original (SCP) IDLH: 10,000 ppm

Basis for original (SCP) IDLH: The chosen IDLH is based on an analogy with butyl acetate and ethyl acetate which have IDLHs of 10,000 ppm.

Short-term exposure guidelines: None developed


Lethal concentration data:

Species Reference LC50 (ppm) LCLo (ppm) Time Adjusted 0.5-hr LC (CF) Derived value



Flury and Wirth 1933

Flury and Wirth 1933

Smyth et al. 1962







4 hr

1 hr

4 hr

22,078 ppm (2.0)

27,191 ppm (1.25)

64,000 ppm (2.0)

2,208 ppm

2,719 ppm

6,400 ppm

Lethal dose data:

Species Reference Route LD50 (mg/kg) LDLo (mg/kg) Adjusted LD Derived value
Rabbit Munch 1972 oral 3,700 ----- 8,409 ppm 841 ppm

Human data: It has been reported that concentrations of 10,000 ppm for a short time caused irritation which persisted after exposure stopped [Clayton and Clayton 1981].

Revised IDLH: 3,100 ppm [LEL]

Basis for revised IDLH: Based on health considerations and acute inhalation toxicity data in humans [Clayton and Clayton 1981], the original value of about 10,000 ppm would have been appropriate for methyl acetate. However, the revised IDLH for methyl acetate is 3,100 ppm based strictly on safety considerations (i.e., being 10% of the lower explosive limit of 3.1%).


1. Clayton GD, Clayton FE, eds. [1981]. Patty’s industrial hygiene and toxicology. 3rd rev. ed. Vol. 2A. Toxicology. New York, NY: John Wiley & Sons, Inc., p. 2272.

2. Flury F, Wirth W [1933]. Zur toxikologie der lösungsmittel (Verschieden ester, aceton, methylalkohol). Arch Gewerbepath Gewerbehyg 5:1-90 (in German).

3. Munch JC [1972]. Aliphatic alcohols and alkyl esters: narcotic and lethal potencies to tadpoles and to rabbits. Ind Med Surg 41:31-33.

4. Smyth HF Jr, Carpenter CP, Weil CS, Pozzani UC, Striegel JA [1962]. Range-finding toxicity data: list VI. Am Ind Hyg Assoc J 23:95-107.

Page last reviewed: December 4, 2014