A review of available sources identified the following: LD50 (dog, mouse, rat) and LC50 (mouse) 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 3.6.2, 3.6.3, 3.6.4, and evaluated using factors in Tables 3.2, 3.3, and 3.4. Although an LC50 is a preferred exposure, the duration could not be confirmed. Of the additional toxicity data evaluated, a rat oral LD50 (7 mg/kg) was selected as the TEEL-3 basis because it generated a sufficiently conservative TEEL-3 value. The magnitude of TEEL value was evaluated by examining its GHS hazard classification; it is indicated to be a level 1 inhalation hazard (“fatal if inhaled”), equivalent to an LC50 of 50 mg/m¬3/TEEL-3 of 2.2 mg/m3 (see GHS Table 3.1.1). This indicates the magnitude of the TEEL-3 resultant from the selected rat oral LD50 is appropriate. 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 (7 mg/kg)
This review generated TEEL values that are inconsistent with those found in Rev 29A. The Rev. 29A bases for TEEL-3 (pig intravenous LD50) and TEEL-2 (monkey intravenous TDLo) were not found during the current review and were therefore revised, based on available data.