A review of available sources identified acute toxicity data (LD50) for several species and routes. In addition, analysts evaluated exposure limits of manganese compounds (CASRN: 7439-96-5, IDLH, ceiling limits, STELs, TWAs) 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, a rat oral LD50, was selected as the TEEL-3 basis. 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 = Rat oral LD50 (2150 mg/kg)
This review generated PAC values consistent with Rev. 29A.