A review of available sources identified an exposure limit (TLV-TWA) and GHS health hazard ratings for indium. Data sources were selected according to the hierarchy listed in Table 3.1. Reported GHS health hazard ratings (H315 and H319, Category 2; H335, Category 3; H302, H312, and H332, Category 4) indicate a mid-level health hazard, approximately equivalent to an HHR=2. Considering this, analysts assumed an HHR=2 as the TEEL-3 basis (Section 3.4.5). The TEEL-2 value was derived according to Table 3.5. The TLV-TWA was selected as the TEEL-1 basis.
• PAC-1 = TEEL-1 = TLV-TWA (0.1 mg/m3) x 3
• PAC-2 = TEEL-2 = TEEL-3/6
• PAC-3 = TEEL-3 = HHR=2
This review generated a PAC-1 value consistent with Rev. 29A, and inconsistent PAC-2 and PAC-3 values. The Rev. 29A and current TEEL-1 value, source, and methodology remain consistent. The Rev. 29A TEEL-2 and TEEL-3 were derived from the TEEL-1 (Table 3.5). The current TEEL-3 basis is an assumed HHR=2 from analysis of GHS health hazard statements, from which the TEEL-2 was derived (Table 3.5).