A review of available sources did not identify exposure limits and limited acute toxicity data (LCLo). Reported GHS health hazard codes (H315 and H319, Category 2; H335, Category 3) for manganese oxalate correspond to an approximate HHR=2 (PAC-2 = TEEL-2 = 790 mg/m3). 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 evaluated 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 mouse LCLo was evaluated as a TEEL-3 basis, however analysts determined an IDLH was more consistent with TEEL methodology (Section 3.1). The 1990 and 1994 IDLH were compared; the 1990 IDLH was derived from the PEL-TWA, while the 1994 IDLH includes animal inhalation acute toxicity data. Considering this, and the estimated TEEL-3 range from reported GHS health hazards, analysts selected the 1994 IDLH as the TEEL-3 basis. The PEL-C was selected as the TEEL-2. The PEL-STEL was selected as the TEEL-1. A compound adjustment factor was applied to 1994 IDLH, PEL-C, and PEL-STEL (Section 3.2.2).
• PAC-1 = TEEL-1 = MW-adjusted PEL-STEL (manganese, CASRN: 7439-96-5; 3 mg/m3)
• TEEL-2 = MW-adjusted PEL-C (manganese, CASRN: 7439-96-5; 5 mg/m3)
• PAC-3 = TEEL-3 = MW-adjusted IDLH (1994, manganese, CASRN: 7439-96-5; 500 mg/m3)
This review generated a PAC-1 value consistent with Rev. 29A and PAC-2 and PAC-3 values inconsistent. The Rev. 29A and current TEEL-1 sources and methodologies are consistent. The TEEL-2 sources and methodology are also consistent; therefore, minor differences in the TEEL-2 value may be due to rounding. The Rev. 29A TEEL-3 was derived from the TEEL-2. The current TEEL-3 basis is a weight adjusted 1994 manganese IDLH, due to its inclusion of inhalation acute toxicity data. The 1994 IDLH was used according to handbook guidelines (Section 4.2-4.3).