HazMat Tool — substance information
Tungsten hexafluoride
HMT 15 June 2026- UN / ID
- UN 2196
- Hazard class
- 2.3
- Packing group
- —
- ERG guide
- ERG 125
- Special provisions
- SP 2, SP N86
- Source
- 49 CFR §172 (15 June 2026)
Tungsten hexafluoride
Tungsten(VI) fluoride, also known as tungsten hexafluoride, is an inorganic compound with the formula WF6. It is a toxic, corrosive, colorless gas, with a density of about 13 kg/m3 (22 lb/cu yd) (roughly 11 times heavier than air). It is the densest known gas under standard ambient temperature and pressure (298 K, 1 atm) and the only well-characterized gas under these conditions that contains a transition metal. WF6 is commonly used by the semiconductor industry to form tungsten films, through the process of chemical vapor deposition Wikipedia
| Emergency Response Guide No. 125 |
Hazardous Materials Table
Source: 49 CFR §172 (15 June 2026)(3) Hazard Class2.3Poisonous gas |
(4) Identification number |
(5) Packing Group |
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(6) Labels |
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(7) Special Provisions (§172.102)
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| 2 | |
|---|---|
| N86 |
(8) Packing Authorizations (§173.***) 
| (8A) Exceptions | None | |
|---|---|---|
| (8B) Non-bulk | 338 | see 49 CFR §173.338 |
| (8C) Bulk | None |
(9) Quantity Limits 
| (9A) Passenger aircraft/rail | Forbidden |
|---|---|
| (9B) Cargo aircraft only | Forbidden |
(10) Vessel stowage 
| (10A) Location | |
|---|---|
| (10B) Other |
Segregation chart for load, transport, and storage
This chart shows whether loading, transport, or storage with other hazard classes is permitted, prohibited, or restricted. Based on 49 CFR §177.848.
Note: In this segregation and separation chart are HazMat of hazard class 2.3 considered depending on their poisonousness by inhalation (Hazard zone B). See special provision 2 and PHMSA Interpretation #09-0252.
| Hazard class | 8![]() | 7![]() | 6.1![]() | 5.2![]() | 5.1![]() | 4.3![]() | 4.2![]() | 4.1![]() | 3![]() | 2.3B![]() | 2.3A![]() | 2.2![]() | 2.1![]() | 1.6![]() | 1.5![]() | 1.4![]() | 1.3![]() | 1.1/1.2![]() |
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1.3 ![]() | ||||||||||||||||||
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1.6 ![]() | ||||||||||||||||||
2.1 ![]() | ||||||||||||||||||
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2.3A ![]() | ||||||||||||||||||
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3 ![]() | ||||||||||||||||||
4.1 ![]() | ||||||||||||||||||
4.2 ![]() | ||||||||||||||||||
4.3 ![]() | ||||||||||||||||||
5.1 ![]() | ||||||||||||||||||
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6.1 ![]() | ||||||||||||||||||
7 ![]() | ||||||||||||||||||
8 ![]() |
| Must not be loaded, transported, or stored together in the same vehicle or facility. | |
| May be loaded, transported, or stored together. | |
| May be loaded, transported, or stored together only with restrictions. |