A review of available sources did not identify exposure limits or acute toxicity data for potassium tellurate. Instead, exposure limits for tellurium (CASRN: 13494-80-9, TLV-TWA, IDLH) and acute toxicity data for a similar chemical (sodium tellurate, CASRN: 10101-83-4) were evaluated for TEEL development. 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 was evaluated as a TEEL-3 basis; however, it was not selected because 1) the IDLH basis did not include tellurates or similar chemicals. Instead, the acute toxicity data for sodium tellurate was selected as a TEEL-3 basis and molecular weight adjusted (Section 3.4.3.2). The TEEL-2 was derived according to Table 3.5. The TLV-TWA for tellurium was selected as the TEEL-1 basis, and a compound adjustment factor 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 = MW-adjusted rat oral LD50 (sodium tellurate, CASRN: 10101-83-4, 385 mg/kg)
This review generated TEEL-3 and TEEL-2 values less conservative than Rev. 29A. The Rev. 29A and current TEEL-1 sources and values are consistent. The Rev. 29A TEEL-2 and TEEL-3 values were derived from the TEEL-1. The current TEEL-3 basis is a molecular weight adjusted acute toxicity for a similar chemical, from which the TEEL-2 is derived.