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CAS number: 65996932
NIOSH REL: 0.1 mg/m3 (cyclohexaneextractable fraction) TWA; NIOSH considers coal tar pitch volatiles to be potential occupational carcinogens as defined by the OSHA carcinogen policy [29 CFR 1990].
Current OSHA PEL: 0.2 mg/m3 (benzenesoluble fraction) TWA
1989 OSHA PEL: Same as current PEL
19931994 ACGIH TLV: 0.2 mg/m3 (benzenesoluble fraction) TWA, A1
Description of Substance: Black or darkbrown amorphous residue.
LEL: . . Unknown
Original (SCP) IDLH: 700 mg/m3 [*Note: "Effective" IDLH = 400 mg/m3 -- see discussion below.]
Basis for original (SCP) IDLH: Redmond et al. [1972] have shown that the major health effects resulting from longterm repeated exposure to coal tar pitch volatiles (CTPV) are cancer of the lung, kidney, and skin; however, no studies have been made on carcinogenic effects by any route from single shortterm exposure to CTPV that could relate to a 30minute IDLH. Therefore, reliance must be placed on comparative data of single versus repeated carcinogenic doses of benzo(a)pyrene [B(a)P], a known component of CTPV. Bingham [1971] reported that B(a)P applied in a single dose of 2 mg to the skin of mice yielded tumors in 10% to 20% of the animals whereas 0.01 mg B(a)P applied in a noncarcinogenic solvent applied to the skin 3 times/week for 50 weeks yielded tumors in 50% of the animals. Thus, a single dose producing about 1/3 the number of tumors was 200 times the repeated 3 times/week dose. Using this factor and the value of 0.6 mg/m3 CTPV reported by Mazumdar et al. [1975] as safe for coke oven workers, a total dose IDLH of 120 mg CTPV (as benzene solubles) is calculated; by using 7.5 liters as the minute volume of coke oven workers and a 75% lung retention of CTPV a 30minute IDLH is calculated to be about 700 mg/m3 (as benzene solubles). However, because of the assigned protection factor afforded by each device, 400 mg/m3 (i.e., 2,000 × the PEL) is the concentration above which only the "most protective" respirators are permitted.
Shortterm exposure guidelines: None developed
ACUTE TOXICITY DATA
Lethal concentration data:
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| Pyrene Rat | Potapova et al. 1971 | 170 mg/m3 | ----- | ? | ? | ? |
Lethal dose data:
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| Pyrene Rat Mouse | Potapova et al. 1971 Potapova et al. 1971 | oral oral | 2,700 800 | ----- ----- | 18,900 mg/m3 5,600 mg/m3 | 1,890 mg/m3 560 mg/m3 |
| Anthracene Mouse | Nogochy 1969 | oral | ----- |
>17,000 | >119,000 mg/m3 | >11,900 mg/m3 |
| Phenanthrene Mouse | Rakhmanina 1964 | oral | 700 | ----- | 4,900 mg/m3 | 490 mg/m3 |
Other animal data: The major health effects resulting from longterm repeated exposure to coal tar pitch volatiles (CTPV) are cancer of the lung, kidney, and skin [Redmond et al. 1972]; however, no studies have been made on carcinogenic effects by any route from single shortterm exposure to CTPV that could relate to a 30minute IDLH. Therefore, reliance must be placed on comparative data of single versus repeated carcinogenic doses of benzo(a)pyrene [B(a)P], a known component of CTPV. It has been reported that B(a)P applied in a single dose of 2 mg to the skin of mice yielded tumors in 10% to 20% of the animals whereas 0.01 mg B(a)P applied in a noncarcinogenic solvent applied to the skin 3 times/week for 50 weeks yielded tumors in 50% of the animals [Bingham 1971]. Thus, a single dose producing about 1/3 the number of tumors was 200 times the repeated 3 times/week dose. Using this factor and the value of 0.6 mg/m3 CTPV reported as safe for coke oven workers [Mazumdar et al. 1975], a total dose IDLH of 120 mg CTPV (as benzene solubles) is calculated; by using 50 liters as the minute volume of workers and 100% lung retention of CTPV, a 30minute IDLH is calculated to be about 80 mg/m3 (as benzene solubles).
Human data: None relevant for use in determining the revised IDLH.
| Revised IDLH: 80 mg/m3 (as the benzenesoluble fraction)
Basis for revised IDLH: The revised IDLH for coal tar pitch volatiles is 80 mg/m3 (as the benzenesoluble fraction) based on toxicity data in animals [Bingham 1971; Mazumdar et al. 1975; Redmond et al. 1972] (see discussion above). [Note: NIOSH recommends as part of its carcinogen policy that the "most protective" respirators be worn for coal tar pitch volatiles at concentrations above 0.1 mg/m3 (cyclohexaneextractable fraction).] |
REFERENCES:
1. Bingham E [1971]. Thresholds in cancer inductions. If they do exist, do they shift? Arch Environ Health 22:692695.
2. Mazumdar S, Redmond C, Sollecito W, Sussman N [1975]. An epidemiological study of exposure to coal tar pitch volatiles among coke oven workers. J Air Pollut Control Assoc 25(4):382389.
3. Nagochy PA [1969]. Comparative study of the toxicity of pure and technical anthracene. Gig Tr Prof Zabol 13(5):59 (in Russian).
4. Potapova AN, Kapitulsky VB, et al. [1971]. Toxicological evaluation of pyrene. Gig Tr Prof Zabol 15(2):59 (in Russian).
5. Rakhmanina NL [1964]. Establishing standards for the phenanthrene and pyrene contents in water bodies. Gig Sanit 29(6):1923 (translated).
6. Redmond CK, Ciocco A, Lloyd JW, Rush HW [1972]. Longterm
mortality study of steel workers. VI. Mortality from malignant
neoplasms among coke oven workers. J Occup Med 14(8):621629.
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