A review of available sources identified a NFPA health hazard rating of 1 for coal tar. In addition, analysts evaluated exposure limits for coal tar pitch volatiles (CTPV, CASRN: 65996-93-2, IDLH, TWA) for TEEL development. Coal tar aerosol will likely contain more than benzene soluble components of the mixture; however, analysts considered this a conservative representation of possible chemical in the mixture. Data sources were selected according to the hierarchy listed in Table 3.1. Analysts selected the CTPV 1990 IDLH as the TEEL-3 (Section 3.4.6, Table 3.1). The TEEL-2 value was derived according to Table 3.5. The CTPV TLV-TWA was selected as the TEEL-1 basis.
• PAC-1 = TEEL-1 = TLV-TWA (CTPV, CASRN: 65996-93-2; 0.2 mg/m3) x 3
• PAC-2 = TEEL-2 = TEEL-3/6
• PAC-3 = TEEL-3 = IDLH (1990, CTPV CASRN: 65996-93-2; 700 mg/m3)
This review generated PAC values inconsistent with Rev. 29A. The Rev. 29A TEEL-3 basis was rabbit dermal LD50, that was not found during this review. Instead, analysts selected an IDLH for coal tar pitch volatiles (CASRN: 65996-93-2). The Rev. 29A and current TEEL-2 use the same methodology, with differences due to the change in TEEL-3. The Rev. 29A TEEL-1 was derived from the TEEL-2, while the current TEEL-1 basis is a TLV-TWA for coal tar pitch volatiles.