Gas Name (Symbol)

NFPA Health Class

UFC Hazard Classes

ammonia (NH₃)

3

C, F(LG)

arsenic pentafluoride (AsF₅)

4

T(H), C, CAR, WR(1)

arsine (AsH₃)

4

T(H), F, F(LG)

benzene in air

—

CAR, F @1.4%, Liquid

boron trichloride (BCl₃)

3

T, C, WR(1)

boron trifluoride (BF₃)

3

T, C, WR(1)

bromine pentafluoride

3

T, C, WR(3), O(3)

bromine trifluoride (BrF₃)

4

T(H), C, WR(3), O

1,3-butadiene (C₄H₆)

4

F, CAR, UR(2), I

carbon monoxide (CO)

2

F(G)

carbonyl fluoride (COF₂)

3

T, I, WR(1)

carbonyl sulfide

3

T, C, F(LG), OHH

chlorine (Cl₂)

3

T, C, O(LG)

chlorine trifluoride (ClF₃)

4

T(H),C,O(LG),UR(3D),WR(2)

cyanogen (C₂N₂)

4

T(H), C, F(G)

cyanogen chloride (ClCN)

4

T(H), I, UR(2), WR(1)

diborane (H6B₂)

4

T(H), P, I, UR(3D), WR(1)

dichlorosilane (SiH₂Cl₂)

3

C, F(LG), WR(1)

fluorine (F₂)

4

T(H), C, WR(2), O(G)

germanium tetrahydride (GeH₄)

4

T(H), I, F(G), UR(3D)

hydrogen bromide (HBr)

2

I

hydrogen chloride (HCl)

3

C

hydrogen cyanide (HCN)

4

T(H), F(LG), UR(2), WR(1)

hydrogen fluoride (HF)

3

T, C, WR(2)

hydrogen selenide (H₂Se)

4

T(H), F(LG), I

hydrogen sulfide (H₂S)

3

T, I, F(LG)

iodine pentafluoride (IP5)

NL

methyl bromide (CH₃Br)

3

T, C, F(LG)

methyl chloride (CH₃Cl)

2

F(LG), WR(1), I

methyl silane

3

nickel carbonyl Ni(CO)₄

4

T(H),I,F,UR(3D),WR(1), Liq

nitric oxide (NO)

3

T, I, O(LG)

nitrogen dioxide (NO₂)

4

T(H), C, O(LG), WR(1)

nitrogen trifluoride (NF₃)

3

I, O(G), OHH

nitrosyl chloride (NOCl)

NL

oxygen difluoride (OF₂)

NL

phosgene (COCl₂)

4

T, I, WR(1)

phosphine (PH₃)

4

T(H), P

phosphorous pentafluoride (PF₅)

3

T, C, WR(1), WR(1)

phosphorous trichloride (PCl₃)

3

T, P, C, UR(2), WR(2), Liquid

phosphorous trifluoride (PF₃)

3

T, I, WR(1)

selenium hexafluoride

NL

silane (silicontetrahydride-SiH₄)

2

P, UR(1)

silicon tetrachloride (SiCl₄)

3

C, WR(1), Liquid

silicon tetrafluoride (SiF₄)

3

T

stibine (SbH₃)

4

T(H), F(G)

sulfur dioxide (SO₂)

2

I

sulfur tetrafluoride (SF₄)

4

T(H), C, UR(2), WR(1)

sulfuryl fluoride (SO₂F₂)

3

T, I

tellurium hexafluoride (TeF₆)

NL

tungsten hexafluoride (WF₆)

3

T, C, WR(2)

vinyl chloride (C₂H₃Cl)

4

T, I, F(LG), UR(1), CAR

Abbreviations:

CAR — Carcinogen

C — Corrosive

F — Flammable: Gas (G), Liquefied Gas (LG)

I — Irritant

NL — Not Listed

O — Oxidizer: Gas (G); Liquefied Gas (LG); Classes (1), (2), (3), and (4)

OHH — Other Health Hazard

T — Toxic: Highly (H)

UR — Unstable Reactive: Classes (1), (2), (3), Detonatable (3D), and (4)

WR — Water Reactive: Classes (1), (2), (3), and (4)