A review of available sources identified exposure limits (OEL-TWA) and acute toxicity data (LC50, LD50) for mice and rats. 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 duration of acute inhalation data (LC50) could not be verified by a reliable source; therefore, this data was not selected for TEEL development (Section 3.3.1). As such, the next most preferred species and route data, 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 (54100 µg/kg)
This review generated TEEL-3 and TEEL-2 values consistent with Rev. 29A. The Rev. 29A, TEEL-1 basis was an OEL-TWA (UK) that was not found during this review. Instead, the TEEL-1 was derived from the TEEL-2 (Table 3.5).