A review of available sources identified the following acute animal toxicity studies (LD50, LDLo). 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 LD50 of the most preferred species and route, a rat oral LD50, was selected as the TEEL-3 basis. TEEL-1 and TEEL-2 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 (84 mg/kg)
This review generated a PAC-2 and PAC-1 values inconsistent with Rev. 29A. The Rev. 29A TEEL-2 basis was a rat oral TDLo that was not found in this review; instead, the TEEL-2 derived from the TEEL-3. The Rev. 29A and current TEEL-1 use the same methodology, with differences due to the change in TEEL-2. The Rev. 29A and current PAC-3 values, source, and methodology are consistent.