Immediately Dangerous to Life or Health Concentrations (IDLH)
CAS number: 142–82–5
NIOSH REL: 85 ppm (350 mg/m3) TWA,
440 ppm (1,800 mg/m3) 15-minute CEILING
Current OSHA PEL: 500 ppm (2,000 mg/m3) TWA
1989 OSHA PEL 400 ppm (1600 mg/m3) TWA, 500 ppm (2,000 mg/m3) STEL
1993-1994 ACGIH TLV: 400 ppm (1,640 mg/m3) TWA, 500 ppm (2,050 mg/m3) STEL
Description of Substance: Colorless liquid with a gasoline-like odor.
LEL:. . 1.05% (10% LEL, 1,050 ppm)
Original (SCP) IDLH: 5,000 ppm
Basis for original (SCP) IDLH: The chosen IDLH is based on the statement by Patty  that a 15-minute exposure to 5,000 ppm produced a state of intoxication characterized by uncontrolled hilarity in some individuals and in others a stupor lasting for 30 minutes after the exposure [Patty and Yant 1929]. According to Patty , a 4-minute exposure to this same concentration produces vertigo and incoordination [Patty and Yant 1929]. These symptoms described by Patty  could perhaps impede escape.
Short-term exposure guidelines: None developed
ACUTE TOXICITY DATA
Lethal concentration data:
|Flury and Zernik 1931|
Swann et al. 1974
28,778 ppm (1.6)
15,000 ppm (1.0)
Other human data: Inhalation of 1,000 ppm for 6 minutes was associated with slight dizziness [Patty and Yant 1929]. Exposure to 5,000 ppm for 4 minutes produced complaints of nausea, a loss of appetite, vertigo, and incoordination [Patty and Yant 1929]. A 15-minute exposure to 5,000 ppm produced a state of intoxication characterized by uncontrolled hilarity in some individuals and in others a stupor lasting for 30 minutes after the exposure [Patty and Yant 1929].
|Revised IDLH: 750 ppm
Basis for revised IDLH: The revised IDLH for n-heptane is 750 ppm based on acute inhalation toxicity data in humans [Patty and Yant 1929].
1. Flury F, Zernik F . Schädliche gase dämpfe, nebel, rauch- und staubarten. Berlin, Germany: Verlag von Julius Springer, pp. 257-264 (in German).
2. Marhold J . Prehled Prumyslove Toxikologie, Organicke Latky. Prague, Czechoslovakia: Avicenum, p. 9 (in Czechoslovakian).
3. Patty FA, ed. . Industrial hygiene and toxicology. 2nd rev. ed. Vol. II. Toxicology. New York, NY: Interscience Publishers, Inc., pp. 1198-1199.
4. Patty FA, Yant WP . Odor intensity and symptoms produced by commercial propane, butane, pentane, hexane, and heptane vapor. Pittsburgh, PA: Department of Commerce, U.S. Bureau of Mines, Report of Investigations, No. 2979, pp. 1-10.
5. Swann HE Jr, Kwon BK, Hogan GK, Snellings WM . Acute
inhalation toxicity of volatile hydrocarbons. Am Ind Hyg
Assoc J 35:511-518.
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