A review of available sources identified acute animal toxicity data (LC, LDLo, LD50). 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. Although inhalation is the most preferred route, the lethality effect of this source could not be determined (LDLo, LD50), therefore it was not appropriate for TEEL development. Instead, the next most preferred species and route, a rat oral LD50, was selected as the TEEL-3 basis. 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 oral LD50 (> 5 g/kg)
This review generated TEEL values are inconsistent with Rev. 29A. The Rev. 29A TEEL-3 basis (rat LCLo) and TEEL-2 basis (rabbit TDLo) were not found in the current review. The Rev. 29A and current TEEL-1 were derived using the same methodology, with differences due to the change in TEEL-2.