A review of available sources identified mouse and rat acute toxicity data (LD50) for intraperitoneal and oral routes. Creosote is a name for an assortment of products, including coal tar creosote, coal tar, coal tar pitch, and coal tar pitch volatiles. Considering this, analysts also evaluated exposure limits (CPTV; IDLH, STELS, TWAs) for a similar chemical, coal tar pitch volatiles (CASRN: 65996-93-2) for TEEL development (Section 3.4.6). Data sources were selected according to the hierarchy listed in Table 3.1. Toxicity data were selected according to type of exposure, species, and route according to the hierarchies stated in Sections 3.3.1, 3.3.2, and evaluated using factors in Tables 3.2, 3.3, and 3.4. The most preferred species and route toxicity data, a rat oral LD50, was selected as the TEEL-3 basis. TEEL-2 and TEEL-1 values were derived according to Table 3.5.
• PAC-1 = TEEL-1 = TEEL-2/11
• PAC-2 = TEEL-2 = TEEL-3/6
• PAC-3 = TEEL-3 = Rat oral LD50 (725 mg/kg)
This review generated PAC values inconsistent with Rev. 29A. The Rev. 29A TEEL-3 was the IDLH for CTPV, while the current TEEL-3 basis is chemical specific toxicity data. The Rev. 29A and current TEEL-2 use the same methodology, with differences due to the change in TEEL-3. The Rev. 29A TEEL-1 basis was a TLV-TWA for CPTV, while the current TEEL-1 was derived from the TEEL-2.