n-Heptane

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 [1963] 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 [1963], a 4-minute exposure to this same concentration produces vertigo and incoordination [Patty and Yant 1929]. These symptoms described by Patty [1963] could perhaps impede escape.

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
Human Mouse Mouse	Flury and Zernik 1931 Marhold 1986 Swann et al. 1974	----- 17,986 -----	16,000 ----- 15,000	? 2 hr 30 min	? 28,778 ppm (1.6) 15,000 ppm (1.0)	? 2,878 ppm 1,500 ppm

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].

REFERENCES:

1. Flury F, Zernik F [1931]. Schädliche gase dämpfe, nebel, rauch- und staubarten. Berlin, Germany: Verlag von Julius Springer, pp. 257-264 (in German).

2. Marhold J [1986]. Prehled Prumyslove Toxikologie, Organicke Latky. Prague, Czechoslovakia: Avicenum, p. 9 (in Czechoslovakian).

3. Patty FA, ed. [1963]. Industrial hygiene and toxicology. 2nd rev. ed. Vol. II. Toxicology. New York, NY: Interscience Publishers, Inc., pp. 1198-1199.

4. Patty FA, Yant WP [1929]. 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 [1974]. Acute inhalation toxicity of volatile hydrocarbons. Am Ind Hyg Assoc J 35:511-518.