A review of available sources identified a WEEL-TWA, and mouse and rat acute toxicity data (LD50) for intraperitoneal and oral 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 source and route toxicity data, a rat oral LD50, was selected as the TEEL-3 basis. TEEL-2 values were derived according to Table 3.5. The WEEL-TWA was selected as the TEEL-1 basis.
• TEEL-1 = WEEL-TWA (0.1 mg/m3) x 3
• TEEL-2 = TEEL-3/6
• TEEL-3 = Rat oral LD50 (157 mg/kg)
This review generated TEEL-3 and TEEL-2 values inconsistent with Rev. 29A. The Rev. 29A TEEL-3 basis was a rat oral LD50; the current TEEL-3 basis is also a rat oral LD50 but is a lower dose. The Rev. 29A TEEL-2 basis was a rat oral TDLo not found during the current review; instead, the TEEL-2 was derived from the TEEL-3 (Table 3.5). The Rev. 29A and current TEEL-1 values, source, and methodology are consistent.