A review of available sources did not identify exposure limits or acute toxicity data for butyric acid sodium salt. Reported GHS health hazard ratings (H315 and H319, Category 2; H335, inhalation Category 3; H302l, Category 4) indicate a mid-to-high level health hazard, approximately equivalent to an HHR=2 (790 mg/m3). In addition, analysts evaluated acute toxicity data (LD50, LDLo) for a similar chemical, butyric acid (CASRN: 107-92-6) for TEEL development (Section 3.4.6). 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 the most preferred species and route toxicity data, a rat oral LD50, for butyric acid as the TEEL-3 basis. GHS health hazards indicate the resultant TEEL is an appropriate magnitude. 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 (butyric acid, CASRN: 107-92-6; 2000 mg/kg)
This review generated PAC values 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 basis rat oral LD50 for butyric acid (Section 3.4.6, CASRN: 107-92-7), from which TEEL-2 and TEEL-1 were derived (Table 3.5).