A review of available sources did not identify exposure limits or acute toxicity data for manganese(II) nitrate. Two of the three reported GHS health hazard codes (H314 and H318) are Category 1 for manganese(II) nitrate, corresponding to an approximate HHR=3 (PAC-3 = TEEL-3 = 79 mg/m3). In addition, analysts evaluated exposure limits of manganese compounds (CASRN: 7439-96-5, IDLH, ceiling limits, STELs, TWAs) for TEEL development. Analysts also considered the solubility of manganese(II) nitrate, which would result in manganese being bioavailable upon inhalation. Data sources were selected according to the hierarchy listed in Table 3.1. The manganese PEL-STEL and PEL-C were selected as the TEEL-1 and TEEL-2, respectively, and a compound adjustment factor was applied (Section 3.2.2). Analysts evaluated the IDLHs (1990, 1994) and the GHS estimated TEEL-3, determining that neither IDLH is sufficiently conservative. Instead, the TEEL-3 was derived according to Table 3.5.
• 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 = TEEL-2 x 6
This review generated PAC-2 and PAC-1 values consistent with Rev. 29A and a PAC-3 inconsistent. The current Rev. 29A TEEL-2 and TEEL-1 sources and methodologies are consistent. The Rev. 29A TEEL-3 source and methodology are consistent; therefore, minor differences in the values may be due to rounding.