Cyclohexene

CAS number: 110–83–8

NIOSH REL: 300 ppm (1,015 mg/m³) TWA

Current OSHA PEL: 300 ppm (1,015 mg/m³) TWA

1989 OSHA PEL: Same as current PEL

1993-1994 ACGIH TLV: 300 ppm (1,010 mg/m³) TWA

Description of Substance" Colorless liquid with a sweet odor.

LEL: . . Unknown

Original (SCP) IDLH: 10,000 ppm

Basis for original (SCP) IDLH: Because very little data are available concerning the effects produced by acute inhalation exposure to cyclohexene, the chosen IDLH is based on an analogy with cyclohexane which has an IDLH of 10,000 ppm.

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
Mouse	Lazarew 1929	-----	13,196	2 hr	21,114 ppm	2,111 ppm

Other animal data: A chronic inhalation study (6 hours/day, 5 days/week for 6 months) in rats, guinea pigs, and rabbits at concentrations of 150, 300, and 600 ppm showed that although significant increases in alkaline phosphatase occurred in all three groups, most of the hematologic parameters measured were within normal limits [Laham 1976].

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

Revised IDLH: 2,000 ppm Basis for revised IDLH: The revised IDLH for cyclohexene is 2,000 ppm based on acute toxicity data in animals [Lazarew 1929]. This may be a conservative value due to the lack of relevant acute toxicity data for workers.

REFERENCES:

1. Laham S [1976]. Inhalation toxicity of cyclohexene (Abstract #152). Toxicol Appl Pharmacol 37(1):155.

2. Lazarew NW [1929]. On the toxicity of various hydrocarbon vapors. Arch Exp Pathol Pharmakol 143:223-233 (translated).