A review of available sources did not identify exposure limits or acute toxicity data for sodium carbonate monohydrate. Instead, TEELs were developed from acute toxicity for sodium carbonate (Na2CO3; CASRN: 497-19-8). 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. Of the available data, the most preferred route and species toxicity dose for sodium carbonate, a human (male) oral LDLo, was selected as the TEEL-3 basis. A molecular weight adjustment was applied (Section 3.4.3.2). 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 = MW-adjusted Human (male) oral LDLo (sodium carbonate, CASRN: 497-19-8, 714 mg/kg)
This review generated TEEL values inconsistent with Rev. 29A. The Rev. 29A TEELs were MW-adjusted TEELs for sodium carbonate; the Rev. 29A TEEL-3 basis was a human (male) oral LDLo . The current TEEL-3 source is also a human (male) oral LDLo for sodium carbonate that was MW-adjusted; however, the current source reports a lower lethal dose. The Rev. 29A and current TEEL-2/TEEL-1 values were derived using the same methodology (Table 3.5), with differences due to the TEEL-3.