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Ethyl formate

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

CAS number: 109–94–4

NIOSH REL: 100 ppm (300 mg/m3) TWA

Current OSHA PEL: 100 ppm (300 mg/m3) TWA

1989 OSHA PEL: Same as current PEL

1993-1994 ACGIH TLV: 100 ppm (303 mg/m3) TWA

Description of Substance: Colorless liquid with a fruity odor.

LEL:. . 2.8% (10% LEL, 2,800 ppm)

Original (SCP) IDLH: 8,000 ppm

Basis for original (SCP) IDLH: The chosen IDLH is based on the statements by Smyth [1956] cited in Patty [1963] and by UCC [1968] that 5 of 6 rats died following a 4-hour exposure to 8,000 ppm and no rats died from a 4-hour exposure to 4,000 ppm.

Short-term exposure guidelines: None developed


Lethal concentration data:

Species Reference LC50(ppm) LCLo(ppm) Time Adjusted 0.5-hrLC (CF) Derivedvalue


Flury and Zernik 1931Smyth 1956

Smyth et al. 1954

—–LC83: 8,000




1.5 hr4 hr

4 hr

14,500 ppm (1.45)16,000 ppm (2.0)

16,000 ppm (2.0)

1,450 ppm1,600 ppm

1,600 ppm


Lethal dose data:

Species Reference Route LD50(mg/kg) LDLo(mg/kg) Adjusted LD Derived value
RatG. pig


Jenner et al. 1964Jenner et al. 1964

Munch 1972







4,205 ppm2,523 ppm

4,716 ppm

421 ppm252 ppm

472 ppm


Other animal data: It has been stated that rats have survived a 4-hour exposure to 4,000 ppm [UCC 1968].

Human data: It has been reported that 330 ppm produced slight eye irritation and rapidly increasing nasal irritation [Flury and Zernik 1931].

Revised IDLH: 1,500 ppmBasis for revised IDLH: The revised IDLH for ethyl formate is 1,500 ppm based on acute inhalation toxicity data in animals [Flury and Zernik 1931; Smyth 1956; Smyth et al. 1954]. This may be a conservative value due to the lack of relevant acute toxicity data for workers at concentrations above 330 ppm.



1. Flury F, Zernik F [1931]. Schädliche gase dämpfe, nebel, rauch- und staubarten. Berlin, Germany: Verlag von Julius Springer, p. 375 (in German).

2. Jenner PM, Hagan EC, Taylor JM, Cook EL, Fitzhugh OG [1964]. Food flavourings and compounds of related structure. I. Acute oral toxicity. Food Cosmet Toxicol 2:327-343.

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. Patty FA, ed. [1963]. Industrial hygiene and toxicology. 2nd rev. ed. Vol. II. Toxicology. New York, NY: Interscience Publishers, Inc., p. 1855.

5. Smyth HF Jr [1956]. Improved communication: hygienic standards for daily inhalation. Am Ind Hyg Assoc Q 17(2):129-185.

6. Smyth HF Jr, Carpenter CP, Weil CS, Pozzani UC [1954]. Range-finding toxicity data: list V. AMA Arch Ind Hyg Occup Med 10:61-68.

7. UCC [1968]. Toxicology studies: ethyl formate. New York, NY: Union Carbide Corporation.