ß-Chloroprene

CAS number: 126–99–8

NIOSH REL: 1 ppm (3.6 mg/m³) 15-minute CEILING; NIOSH considers ß-chloroprene to be a potential occupational carcinogen as defined by the OSHA carcinogen policy [29 CFR 1990].

Current OSHA PEL: 25 ppm (90 mg/m³) TWA [skin]

1989 OSHA PEL: 10 ppm (35 mg/m³) TWA [skin]

1993-1994 ACGIH TLV: 10 ppm (36 mg/m³) TWA [skin]

Description of Substance: Colorless liquid with a pungent, ether-like odor.

LEL: . . 4.0% (10% LEL, 4,000 ppm)

Original (SCP) IDLH: 400 ppm

Basis for original (SCP) IDLH: The chosen IDLH is based on the statement by Patty [1963] that no mice died from a 1-hour exposure to 277 ppm, but all mice died from a 1-hour exposure to 829.2 ppm [von Oettingen et al. 1936].

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
Rat Mouse Rabbit Cat	Izmerov et al. 1982 von Oettingen et al. 1936 von Oettingen et al. 1936 von Oettingen et al. 1936	3,207 LC100: 829 ----- -----	----- ----- 1,052 350	4 hr 1 hr 8 hr 8 hr	6,414 ppm (2.0) 1,036 ppm (1.25) 2,629 ppm (2.5) 876 ppm (2.5)	641 ppm 104 ppm 263 ppm 88 ppm

Human data: Exposure to 973 ppm has resulted in nausea and giddiness in volunteers in 10 to 15 minutes [Nystrom 1948]. Extreme fatigue and unbearable chest pain has occurred following a month of exposure to concentrations ranging from 56 to 334 ppm [Nystrom 1948].

Revised IDLH: 300 ppm Basis for revised IDLH: The revised IDLH for ß-chloroprene is 300 ppm based on acute inhalation toxicity data in humans [Nystrom 1948]. [Note: NIOSH recommends as part of its carcinogen policy that the "most protective" respirators be worn for ß-chloroprene at concentrations above 1 ppm.]

REFERENCES:

1. Izmerov NF, Sanotsky IV, Sidorov KK [1982]. Toxicometric parameters of industrial toxic chemicals under single exposure. Moscow, Russia: Centre of International Projects, GKNT, p. 38.

2. Nystrom AE [1948]. Health hazards in the chloroprene rubber industry and their prevention. A clinical and experimental study, with special reference to chloroprene and its oxidation and polymerization products. Acta Med Scand 123 (Suppl 219):5-125.

3. Patty FA, ed. [1963]. Industrial hygiene and toxicology. 2nd rev. ed. Vol. II. Toxicology. New York, NY: Interscience Publishers, Inc., p. 1320.

4. von Oettingen WF, Hueper WC, Deichmann-Grubler W, Wiley FH [1936]. 2-Chlorobutadiene (chloroprene): its toxicity and pathology and the mechanism of its action. J Ind Hyg Toxicol 18 (4):247-249.