A review of available sources did not identify exposure limits or acute toxicity data for vanadium sulfate. However, 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. The 1994 IDLH lists the basis "as V" (vanadium), while the 1990 IDLH value its basis "as V2O5" (vanadium pentoxide). Considering this, the current review determined that the 1994 IDLH for elemental vanadium was appropriate for TEEL-3 development, it was selected as the TEEL-3. 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 ceiling limit, the PEL-C, was selected as the TEEL-2. A compound adjustment factor was applied to these exposure limits (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: 1314-61-1, 0.5 mg/m³)
• TEEL-3 = MW-adjusted IDLH (1994, vanadium, 35 mg/m3)
This review generated TEEL-2 and TEEL-1 values inconsistent with Rev. 29A. The Rev. 29A and current TEEL-3 values, source, and methodology are consistent. The 1994 IDLH was used according to Handbook guidelines (Section 4.2-4.3). 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.