Petroleum distillates (naphtha)

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

CAS number: 8002–05–9

NIOSH REL: 350 mg/m3 TWA, 1,800 mg/m3 15-minute CEILING

Current OSHA PEL: 500 ppm (2,000 mg/m3) TWA

1989 OSHA PEL: 400 ppm (1,600 mg/m3) TWA

1993-1994 ACGIH TLV: 400 ppm (1,590 mg/m3) TWA

Description of substance: Colorless liquid with a gasoline- or kerosene-like odor.

LEL: . . 1.1% (10% LEL, 1,100 ppm)

Original (SCP) IDLH: 10,000 ppm

Basis for original (SCP) IDLH: The chosen IDLH is based on the statement by AIHA [1963] that the atmospheric concentrations immediately hazardous to life are from 10,000 to 20,000 ppm [Henderson and Haggard 1943]. In addition, the short exposure tolerance to petroleum naphtha is based on a statement by AIHA [1963] that 4,000 to 7,000 ppm may be tolerated for 1 hour [Henderson and Haggard 1943], but not without development of definite symptoms of narcosis [Drinker et al. 1943].

Short-term exposure guidelines: None developed


Animal data: None relevant for use in determining the revised IDLH.

Human data: It has been reported that concentrations of 10,000 to 20,000 ppm are immediately dangerous to health [Henderson and Haggard 1943]. It has also been stated that concentrations of 4,000 to 7,000 ppm could be tolerated for 1 hour, but not without definite symptoms of narcosis [Drinker et al. 1943].

Revised IDLH: 1,100 ppm [LEL]

Basis for revised IDLH: Based on health considerations and acute inhalation toxicity data in humans [Drinker et al. 1943; Henderson and Haggard 1943], a value of about 4,000 ppm would have been appropriate for petroleum distillates (naphtha). However, the revised IDLH for petroleum distillates (naphtha) is 1,100 ppm based strictly on safety considerations (i.e., being 10% of the lower explosive limit of 1.1%).


1. AIHA [1963]. Petroleum naphtha. In: Hygienic guide series. Am Ind Hyg Assoc J 24:427-428.

2. Drinker P, Yaglou CP, Warren MF [1943]. The threshold toxicity of gasoline vapor. J Ind Hyg Toxicol 25:225-232.

3. Henderson Y, Haggard HW [1943]. Noxious gases. 2nd ed. New York, NY: Reinhold Publishing Corporation, p. 192.

Page last reviewed: December 4, 2014