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

CAS numbers: 53469-21-9 (42% Cl); 11097-69-1 (54% Cl)

NIOSH REL: 0.001 mg/m3 TWA; NIOSH considers chlorodiphenyl to be a potential occupational carcinogen as defined by the OSHA carcinogen policy [29 CFR 1990].

Current OSHA PEL: 42% Cl: 1 mg/m3 TWA [skin];

54% Cl: 0.5 mg/m3 TWA [skin]

1989 OSHA PEL: Same as current PEL

1993-1994 ACGIH TLV: 1 mg/m3 TWA [skin]; 0.5 mg/m3 TWA [skin] (54% Cl)

Description of Substance: Colorless to light-colored, viscous liquid with a mild, hydrocarbon odor.

LEL: . . Noncombustible Liquid

Original (SCP) IDLH for chlorodiphenyl (42% Cl): 10 mg/m3

Basis for original (SCP) IDLH: In the absence of any other toxicological data, the chosen IDLH is based on the human TCLO (resulting in an irritant effect) of 10 mg/m3 [Elkins 1959 cited by NIOSH 1976].

Original (SCP) IDLH for chlorodiphenyl (54% Cl): 5 mg/m3

Basis for original (SCP) IDLH: In the absence of human exposure data or data on acute animal exposure, data on chronic animal exposures were used to determine the IDLH. The chosen IDLH is based on inhalation exposure data reported by AIHA [1965] that indicated liver damage occurs in rats chronically exposed (7 hours/day for 83 exposures during 121 days) to 5.4 mg/m3 chlorodiphenyl (54% chlorine) [Treon et al. 1956].

Short-term exposure guidelines: None developed


Lethal dose data:







Adjusted LD


Tanaka et al. 1969oral1,900-----13,300 mg/m31,330 mg/m3
Chlorodiphenyl (42% C) RatBruckner et al. 1973oral4,250
-----29,750 mg/m32,975 mg/m3
Chlorodiphenyl (54% Cl)
Garihoff et al. 1981
-----7,070 mg/m3707 mg/m3

Other animal data: Chlorodiphenyl (42% Cl) had no discernable effects in cats, rabbits, guinea pigs, rats, and mice after 150 seven-hour exposures to 1.9 mg/m3 over 7 months [Treon et al. 1956]; 17 seven-hour exposures over 24 days at 8.6 mg/m3 also appeared to be noninjurious [Treon et al. 1956]. Slight, reversible, nonspecific liver injury was noted in cats, rabbits, guinea pigs, rats, and mice exposed to 1.5 mg/m3 of chlorodiphenyl (54% Cl) for 7 hours/day for 150 days; 5.4 mg/m3 resulted in more extensive but reversible liver damage [Treon et al. 1956].

Human data: It has been reported that concentrations above 10 mg/m3 were unbearably irritating [Elkins 1959]. Several deaths due to atrophy of the liver have occurred among workers chronically exposed to the fumes of chlorodiphenyls and chloronaphthalenes [von Wedel et al. 1943].

Revised IDLH: 5 mg/m3

Basis for revised IDLH: The revised IDLH for chlorodiphenyl is 5 mg/m3 based on acute inhalation toxicity data in humans [Elkins 1959] and animals [Treon et al. 1956]. [Note: NIOSH recommends as part of its carcinogen policy that the "most protective" respirators be worn for chlorodiphenyl at concentrations above 0.001 mg/m3.]


1. AIHA [1965]. Chlorodiphenyls (containing 42% and 54% chlorine). In: Hygienic guide series. Am Ind Hyg Assoc J 26:92-94.

2. Bruckner JV, Khanna KL, Cornish HH [1973]. Biological responses of the rat to polychlorinated biphenyls. Toxicol Appl Pharmacol 24:434-448.

3. Elkins HB [1959]. Chemistry of industrial toxicology. 2nd ed. New York, NY: John Wiley & Sons, Inc., p. 153.

4. Garihoff LH, Cerra FE, Marks EM [1981]. Blood chemistry alterations in rats after single and multiple gavage administration of polychlorinated biphenyl. Toxicol Appl Pharmacol 60:33-44.

5. NIOSH [1976]. TQ13560. Polychlorinated biphenyl (Aroclor 1242). In: Registry of toxic effects of chemical substances, 1976 ed. Cincinnati, OH: U.S. Department of Health, Education, and Welfare, Public Health Service, Center for Disease Control, National Institute for Occupational Safety and Health, DHEW (NIOSH) Publication No. 76-191, p. 944.

6. Tanaka K, Fujita S, Komatsu F, Tamura N [1969]. Experimental subacute poisoning of chlorobiphenyls, particularly the influence on the serum lipids in rats. Fukuoka Igaku Zasshi 60(6):544-547 (in Japanese).

7. Treon JF, Cleveland FP, Cappel J, Atchley RW [1956]. The toxicity of the vapors of Aroclor 1242® and Aroclor 1254®. Am Ind Hyg Assoc Q 17:204-213.

8. von Wedel, Holla WA, Denton J [1943]. Observations on the toxic effects resulting from exposure to chlorinated naphthalene and chlorinated phenyls with suggestions for prevention. Rubber Age 53:419-426.

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