A review of available sources identified an exposure limit (OEL-TWA) and acute toxicity data (LD50) for ceric oxide. 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 reported at PubChem (>5 g/kg) was evaluated, however ECHA reports no adverse effects or deaths at the level. Considering this, analysts selected the OEL-TWA (Latvia) as the TEEL-1 basis. TEEL-2 and TEEL-3 values were derived according to Table 3.5.
• PAC-1 = TEEL-1 = OEL-TWA (5 mg/m3) x 3
• PAC-2 = TEEL-2 = TEEL-1 x 11
• PAC-3 = TEEL-3 = TEEL-2 x 6
This review generated PAC values inconsistent with Rev. 29A. The Rev. 29A TEEL-3 basis was a rat LD50 evaluated during this review that was determined to have no adverse toxic effects, from which TEEL-2 and TEEL-1 values were derived. The current TEEL-1 basis is an OEL-TWA, from which TEEL-2 and TEEL-3 values were derived (Table 3.5.).