Technical Basis
A review of available sources did not identify exposure limits or acute toxicity data for copper(II) sulfide. Instead, analysts evaluated exposure limits (OEL-STEL, OEL-TWA) for inorganic copper compounds (CASRN: 7440-50-8) for TEEL development (Section 3.4.6). Data sources were selected according to the hierarchy listed in Table 3.1. The lowest reported inhalable fraction (Switzerland, 15-minute) was selected as the TEEL-1 basis and a compound adjustment factor was applied (Section 3.2.2). TEEL-2 and TEEL-3 values were derived according to Table 3.5.
• PAC-1 = TEEL-1 = MW-adjusted OEL-STEL (inorganic copper compound, Switzerland, CASRN: 7440-50-8; 0.2 mg/m3)
• PAC-2 = TEEL-2 = TEEL-1 x 11
• PAC-3 = TEEL-3 = TEEL-2 x 6
This review generated PAC values inconsistent with Rev. 29A. The Rev. 29A TEEL-1 basis was a weight adjusted TLV-TWA for copper, while the current TEEL-1 basis is a weight adjusted OEL-STEL (Table 3.5, see Note).