A review of available sources identified acute toxicity data (LD50, LC50) for several species and routes. In addition, exposure limits for antimony (Sb, CASRN: 7440-36-0, IDLH, TWAs) were evaluated for TEEL development. Data sources were selected according to the hierarchy listed in Table 3.1. Toxicity data were selected 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 most preferred species and route toxicity data, a rat LC50, was selected as the TEEL-3 basis and it was scaled to 60-minute equivalent using the ten Berge equation (Section 3.3.4). The resulting TEEL-3 is more conservative than a weight adjusted IDLH, which analysts consider appropriate due to the corrosive properties of this compound. The TEEL-2 value was derived according to Table 3.5. The antimony TLV-TWA was selected as the TEEL-1 basis and a compound adjustment factor was applied (Section 3.2.2).
• TEEL-1 = MW-adjusted TLV-TWA (antimony, CASRN: 7440-36-0, 0.5 mg/m3) x 3
• TEEL-2 = TEEL-3/6
• TEEL-3 = Rat LC50 (720 mg/m3/2H)
This review generated TEEL-3 and TEEL-2 values inconsistent with Rev. 29A. The Rev. 29A TEEL-3 basis was MW-adjusted antimony IDLH (1990); instead, the current TEEL-3 was derived from rat inhalation data for antimony pentachloride. The Rev. 29A and current TEEL-2 use the same methodology, with differences due to the change in TEEL-3. The Rev. 29A and current TEEL-1 values, source, and methodology are consistent.