Cyclopentadiene

IDLH Documentation

CAS number: 542­92­7

NIOSH REL: 75 ppm (200 mg/m3) TWA

Current OSHA PEL: 75 ppm (200 mg/m3) TWA

1989 OSHA PEL: Same as current PEL

1993­1994 ACGIH TLV: 75 ppm (203 mg/m3) TWA

Description of Substance: Colorless liquid with an irritating, terpene­like odor.

LEL: . . Unknown

Original (SCP) IDLH: 2,000 ppm

Basis for original (SCP) IDLH: The chosen IDLH is based on the statement by Deichmann and Gerarde [1969] that 4 of 6 rats died from a 4­hour exposure to 2,000 ppm [Smyth et al. 1954].

Short­term 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

Rat
Shashkina 1965

Shashkina 1965

Smyth et al. 1954
14,182

5,091

LC67: 2,000
-----

-----

-----
2 hr

2 hr

4 hr
22,691 ppm (1.6)

8,146 ppm (1.6)

4,000 ppm (2.0)
2,269 ppm

815 ppm

400 ppm


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

Revised IDLH: 750 ppm

Basis for revised IDLH: The revised IDLH for cyclopentadiene is 750 ppm based on acute inhalation toxicity data in animals [Shashkina 1965]. [Note: It was decided to use the 2­hour lethal concentration data in mice rather than the 4­hour lethal concentration data in rats so as not to magnify the conservatism already present in the correction factors.]


REFERENCES:

1. Deichmann WB, Gerarde HW [1969]. Table 48. Acute toxicity of hydrocarbons. In: Toxicology of drugs and chemicals. New York, NY: Academic Press, Inc., p. 734.

2. Shashkina LF [1965]. Materials for substantiation of maximum permissible concentration of cyclopentadiene and of its dimer -- dicyclopentadiene -- in the atmosphere of industrial premises. Gig Tr Prof Zabol 9(12):13­19 (in Russian).

3. Smyth HF Jr, Carpenter CP, Weil CS, Pozzani UC [1954]. Range­finding toxicity data: list V. AMA Arch Ind Hyg Occup Med 10:61­68.
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