Uranium hexafluoride

Agent Name
Uranium hexafluoride
CAS Number
7783-81-5
Formula
F6-U
Major Category
Toxic Gases & Vapors
Uranium hexafluoride formula graphical representation
Synonyms
Uranium fluoride (UF6); Uranyl fluoride; Uranium hexafluoride, fissile (with more than 1% U-235) [UN2977]; Uranium hexafluoride, fissile excepted or non-fissile [UN2978] [ChemIDplus]
Category
Other Toxic Gases & Vapors
Description
Colorless to white crystals; [HSDB]
Sources/Uses
Used to manufacture fuel for nuclear power; [CAMEO] Uranium ore is produced from underground and open-pit mines. From the ores, uranium mills produce yellowcake, which is a complex mixture containing 80-96% uranium. The yellowcake is used to produce nuclear fuel. [PMID 14691274 ] In the nuclear fuel cycle, yellowcake is converted into uranium hexafluoride gas, which is fed through centrifuges repeatedly to separate isotopes until uranium is enriched. The low-level enriched uranium is used for nuclear fuel while the highly enriched can be used in nuclear weapons. [BBC News]
Comments
Sublimes at room temperature; Reacts with water releasing uranyl fluoride and hydrogen fluoride; [HSDB] Low-level radioactive; "Chemical hazard greatly exceeds radiation hazard." Reacts with water to generate hydrogen fluoride gas; [CAMEO] See "Uranium" and the linked occupational disease.
Biomedical References

Exposure Assessment

BEI
Fluorides in urine = 2 mg/L prior to shift or 3 mg/L at end of shift; (Repeated measurements recommended.) Uranium in urine = 200 ug/L at end of shift;
TIH
Yes
TLV (ACGIH)
0.2 mg/m3, as U (2.5 mg/m3, as F)
Dangerous When Wet
Yes
STEL (ACGIH)
0.6 mg/m3, as U (2.5 mg/m3, as F)
PEL (OSHA)
0.05 mg/m3, as U (sol), 0.25 mg/m3, as U (insol) [2.5 mg/m3, as F]
MAK
1 mg/m3, as F, inhalable fraction
IDLH (NIOSH)
10 mg/m3, as U
Vapor Pressure
115 mm Hg
Explanatory Notes
Melting point = 64.8 degrees C; [Merck Index, 9856] Soluble in chloroform; Decomposes in water; [ATSDR ToxProfiles] Not TIH in land-based spills, but TiH substance released when spilled in water; [ERG 2016] VP from HSDB;
ERPG-1
5 mg/m3
ERPG-2
15 mg/m3
ERPG-3
30 mg/m3

Adverse Effects

Toxic Pneumonitis
Yes
Dermatotoxin
Skin burns

Diseases, Processes, and Activities Linked to This Agent

Diseases

Occupational diseases associated with exposure to this agent:

Processes

Industrial Processes with risk of exposure: