PAC Database - Detailed Chemical Data

Chemical Identity
Chemical CAS# UN# Health Code Numbers
Tungsten hexafluoride 7783-82-6 2196
14.01
4.01
11.01
14.02
11.00
3.02
3.10
10.00
4.11
Formula Synonyms
F6W TUNGSTEN HEXAFLUORIDE, HEXAFLUOROTUNGSTEN, HEXAFLUORURE DE TUNGSTÈNE (DOT FRENCH), HEXAFLUORURO DE TUNGSTENO (DOT SPANISH), TUNGSTEN FLUORIDE, TUNGSTEN FLUORIDE (WF6), TUNGSTEN HEXAFLUORIDE (WF6), TUNGSTEN(6+) FLUORIDE, WOLFRAM HEXAFLUORIDE
Physical Properties
Mol Wt State MP (°C) BP (°C) VP (Hg) VP (°C) SG LEL (ppm)
297.85 G 2.3 17.5 13.069
PAC Values
PAC Values (Original Units: ppm)
PAC-1 PAC-2 PAC-3
1.0 24 44
Converted PAC Values (mg/m3)
PAC-1 PAC-2 PAC-3
12 290 540
Technical Basis
A review did not identify exposure limits or suitable acute toxicity data for tungsten hexafluoride for TEEL development (available LC50 records incomplete). Instead, the review evaluated exposure limits for the following chemicals: tungsten (W, CASRN: 744-33-7), fluorides (CASRN: 16984-48-8), and hydrogen fluoride (HF, CASRN: 7664-39-3). Data sources were selected according to the hierarchy listed in Table 3.1. Tungsten hexafluoride forms hydrogen fluoride upon exposure to moisture, even in ambient conditions; therefore, the AEGLs for hydrogen fluoride were selected as the TEELs for tungsten hexafluoride No compound adjustment factors were used because section 3.2.2. specifies that they are not applied to AEGLs.
• TEEL-1 = AEGL-1 (hydrogen fluoride, CASRN: 7664-39-3)
• TEEL-2 = AEGL-2 (hydrogen fluoride, CASRN: 7664-39-3)
• TEEL-3 = AEGL-3 (hydrogen fluoride, CASRN: 7664-39-3)
This review generated TEEL values less conservative that Rev. 29A. The Rev. 29A reported the TEEL-1 as a TLV-STEL for insoluble tungsten (CASRN:7440-33-7) with a compound adjustment factor applied; TEEL-2 and TEEL-3 values were derived from this TEEL-3. Instead, the current review considered the corrosive byproduct of tungsten hexafluoride hydrolysis and selected hydrogen fluoride AEGLs (CASRN: 7664-39-3) as TEELs, a higher priority source (Section 1).
References
Tungsten hexafluoride information: https://pubchem.ncbi.nlm.nih.gov/compound/Tungsten-hexafluoride
WF6 hydrolysis byproducts: https://doi.org/10.1016/j.jiec.2018.10.024
Hydrogen fluoride AEGL: https://www.epa.gov/aegl/hydrogen-fluoride-results-aegl-program
Tungsten exposure limits: https://www.osha.gov/chemicaldata/524
Fluorides exposure limits: https://www.osha.gov/chemicaldata/806
Search Again
PAC values marked with a subscript "A" correspond to 60-minute AEGL values.
PAC values marked with a subscript "E" correspond to ERPG values.
PAC values marked by * are >= 10% lower explosive limit (LEL) but < 50% LEL.
PAC values marked by ** are > 50% LEL but < 100% LEL.
PAC values marked by *** are >= LEL.