A review of available sources identified acute toxicity data (LD50, LDLo) for various 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 species and route data, a rat oral LD50, was selected as the TEEL-3 basis. TEEL-1 and TEEL-2 values were derived according to Table 3.
• PAC-1 = TEEL-1 = TEEL-2/11
• PAC-2 = TEEL-2 = TEEL-3/6
• PAC-3 = TEEL-3 = Rat oral LD50 (751 mg/kg)
This review generated a PAC-3 value consistent with Rev. 29A, and inconsistent PAC-2 and PAC-1 values. The Rev. 29A and current TEEL-3 values, source, and methodology remain consistent. The Rev. 29A TEEL-2 basis was a rat oral TDLo that was not found in the current review, and instead was derived from the TEEL-3 (Table 3.5). The Rev. 29A and current TEEL-1 methodology remains consistent, with differences in values due to the change of the TEEL-2.