A review of available sources identified acute toxicity data (LC¬50, LD50, LDLo) for several species and routes. In addition, 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 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 vanadium IDLH was considered as a TEEL-3, however analysts selected from the available acute toxicity data available, given that this corresponds to the actual toxicity of ammonium vanadate. The 4-hour rat LC50 was considered as a basis, however it was determined overly conservative because it was the same order of magnitude as the ceiling limits. Instead, the rat oral LD50 was selected as the TEEL-3 basis. 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 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 (58100 µg/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 ammonium vanadate. 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 use the same methodology (Table 3.5), with differences due to the change in TEEL-2.