A review of available sources identified the following: intraperitoneal LD50 (mouse, rat) acute toxicity data. 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 rat LD50 was selected as the TEEL-3 basis because 1) it was the more preferred species (Table 3.5), and 2) it resulted in a more conservative TEEL value. TEEL-2 and TEEL-1 values were derived according to Table 3.5.
• TEEL-1 = TEEL-2/11
• TEEL-2 = TEEL-3/6
• TEEL-3 = Rat intraperitoneal LD50 (0.32 µg/kg)
This review generated TEEL values less conservative than Rev. 29A. The Rev. 29A TEEL-3 basis was not found during this review; instead, available acute toxicity data was evaluated and the most preferred species, resulting in the more conservative TEEL-3 value, was selected – a rat intraperitoneal LD50. The Rev. 29A and current TEEL-2 and TEEL-1 values were derived using the same methodology (Table 3.5), with differences due to the change in TEEL-3.