A review of available sources identified did not identify exposure limits or acute toxicity data for manganese(II) sulfate monohydrate. Instead, analysts evaluated exposure limits of manganese compounds (CASRN: 7439-96-5, IDLH, ceiling limits, STELs, TWAs) and acute toxicity data for manganous sulfate (MnSO4, CASRN: 7785-87-7) 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 most preferred species and route toxicity data for manganous sulfate, a rat oral LD50, was selected as the TEEL-3 basis and it was weight adjusted (Section 3.4.3.2). The manganese PEL-C was selected as the TEEL-2 and a compound adjustment factor was applied per Section 3.2.2. The manganese PEL-STEL was selected as the TEEL-1 basis and a compound adjustment factor was applied per Section 3.2.2.
• PAC-1 = TEEL-1 = MW-adjusted PEL-STEL (manganese, CASRN: 7439-96-5; 3 mg/m3)
• PAC-2 = TEEL-2 = MW-adjusted PEL-C (manganese, CASRN: 7439-96-5; 5 mg/m3)
• PAC-3 = TEEL-3 = MW-adjusted rat oral LD50 (manganous sulfate, CASRN: 7785-87-7; 2150 mg/kg)
This review generated PAC-2 and PAC-1 values consistent with Rev. 29A and a PAC-3 inconsistent. The Rev. 29A and current TEEL-3 value is inconsistent. The Rev. 29A TEEL-3 was derived from the TEEL-2, while the current basis is a rat oral LD50 is both more similar to manganese(II) sulfate monohydrate than elemental manganese and a more preferred source (Section 3.4).