A review of available sources identified the following: a LOC and acute toxicity data (LDLo, LD50) for several species and routes in addition to exposure limits for tellurium (CASRN: 13494-80-9, TLV-TWA, IDLH). 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 IDLH and LOC (0.02 g/m3) were evaluated as potential TEEL bases because they are preferred sources; however, neither was selected result in a sodium tellurite TEEL-3 greater than tellurium, which is inconsistent with expected relative toxicity. Instead, a human LDLo, male assumed, was selected as the TEEL-3 basis and the TEEL-2 value derived according to Table 3.5. The tellurium TLV-TWA was selected as the TEEL-1 basis and a compound adjustment factor was applied (Section 3.2.2).
• TEEL-1 = MW-adjusted TLV-TWA (tellurium, CASRN: 13494-80-9, 0.1 mg/m3) x 3
• TEEL-2 = TEEL-3/6
• TEEL-3 = Human (male, assumed) oral LDLo (30 mg/kg)
This review generated TEEL values more conservative than Rev. 29A. The Rev. 29A TEEL-2 was the LOC, from which TEEL-3 values were derived. The current TEEL-3 basis is a human (male, assumed) oral LDLo; a TEEL-2 was derived from this TEEL-3. The Rev. 29A TEEL-1 was derived from the TEEL-2, while the current basis is a TLV-TWA.