A review of available sources identified mouse acute toxicity data (LD50) for numerous 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 data, mouse 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 = Mouse oral LD50 (920 mg/kg)
This review generated PAC values inconsistent with Rev. 29A. The Rev. 29A TEEL-3 basis was a mouse intraperitoneal LD50, while the current basis is a more preferred route data, mouse oral LD50 (oral > intraperitoneal, Section 3.2.2). The Rev. 29A and current TEEL-2 and TEEL-1 methodologies remain consistent, with differences in values due to the change of the TEEL-3 basis.