A review of available sources identified rat acute toxicity data (oral LD50). there are available exposure limits for vanadium (V as V₂O₅; CASRN: 1314-62-1, IDLH, PEL-C, REL-C, TWAs) and vanadium pentoxide (CASRN: 1314-62-1; LOC). Data sources were selected according to the hierarchy listed in Table 3.1. Toxicity data was evaluated using factors in Tables 3.2, 3.3, and 3.4. The vanadium IDLH was considered as a TEEL-3, however analysts selected the toxicity data, a rat oral LD50, as the TEEL-3 basis given that this data corresponds to the actual toxicity and corrosivity of vanadium tetrachloride. The LOC was considered as a TEEL-2; however, this value was not selected because 1) it is derived from the IDLH, which was not selected as a TEEL-3, and 2) it is an order of magnitude greater than other TEEL-2 available bases (ceiling limits, TWAs; Section 3.3.1). Instead, the most preferred vanadium ceiling limit, the PEL-C, was selected as the TEEL-2 and a compound adjustment factor was applied (Section 3.2.2). The TEEL-1 value was derived according to Table 3.5.
• TEEL-1 = TEEL-2/11
• TEEL-2 = MW-adjusted PEL-C (vanadium dust, as V₂O₅, CASRN: 1314-62-1, 0.5 mg/m³)
• TEEL-3 = Rat oral LD50 (160 mg/kg)
This review generated TEEL values inconsistent with Rev. 29A. The Rev. 29A TEEL-3 was a molecular weight adjusted vanadium IDLH, while the current basis is a rat oral LD50 for vanadium tetrachloride. The Rev.29A TEEL-2 was a molecular weight adjusted REL-C, while the current TEEL-2 is a molecular weight adjusted PEL-C, a more preferred source (Table 3.1). The Rev. 29A and current TEEL-1 values were derived using the same methodology (Table 3.5), with differences due to the change in TEEL-2.