A review of available sources identified exposure limits (WEEL-TWA) and acute toxicity data (LD50, LDLo) for several species and routes. 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 route and species toxicity data, a human (female) oral LDLo was selected as the TEEL-3 basis. The TEEL-2 value was derived according to Table 3.5. The WEEL-TWA was selected as the TEEL-1 basis.
• PAC-1 = TEEL-1 = WEEL-TWA (0.5 mg/m3) x 3
• PAC-2 = TEEL-2 = TEEL-3/6
• PAC-3 = TEEL-3 = Human (female) oral LDLo (400 mg/kg)
This review generated PAC-3 and PAC-2 values inconsistent with Rev. 29A, and a PAC-1 value consistent with Rev. 29A. The Rev. 29A TEEL-3 basis was a rat oral LD50, while the current TEEL-3 basis is human toxicity data (oral LDLo), a more preferred source (Section 3.3.2). The Rev. 29A TEEL-2 basis was a rat TCLo not found during the current review. Instead, the TEEL-2 was derived from the TEEL-3 (Table 3.5). The Rev. 29A and current TEEL-1 values, source, and methodology are consistent.