A review of available sources did not identify exposure limits or acute toxicity data for ethenysilanetriol triacetate. Reported GHS health hazard ratings (H314 and H318, Category 1) indicate a mid to high-level health hazard, approximately equivalent to an HHR=2. Analysts also evaluated acute toxicity data (LD50) for a similar chemical, methylsilanetriyl triacetate (CASRN: 4253-34-3), 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. Analysts selected a rat oral LD50 for methylsilanetriyl triacetate as the TEEL-3 basis (Section 3.4.6). TEEL-2 and TEEL-1 values were derived according to Table 3.5.
• PAC-1 = TEEL-1 = TEEL-2/11
• PAC-2 = TEEL-2 = TEEL-3/6
• PAC-3 = TEEL-3 = Rat Oral LD50 (methylsilanetriyl triacetate, CASRN: 4253-34-3; 1600 mg/kg)
This review generated PAC values that are inconsistent with Rev. 29A. The Rev. 29A TEEL-1 basis was a TLV-TWA for particles not otherwise specified (Section 3.5.2), from which the TEEL-2 and TEEL-3 were derived (Table 3.5). The current TEEL-3 is a rat oral LD50 for a similar chemical (Section 3.4.6), from which the TEEL-2 and TEEL-1 were derived (Table 3.5).