Class 2 gases and compressed-gas confusion

Difference between green compressed gas and poison gas tank label 49 cfr test picture dri…

They are different divisions of Class 2. A green placard is a non-flammable, non-toxic compressed gas (Division 2.2). A poison or toxic gas is Division 2.3, which uses a white placard with a skull and crossbones. Same class number, very different color and symbol.

Difference between green compressed gas and poison gas tank label 49 cfr test picture dri… · CDL Placards Hazmat placard practice

Green means non-flammable gas (2.2)

A green diamond marks a compressed gas that is neither flammable nor toxic, Division 2.2. It carries a 2 at the bottom and usually a gas-cylinder symbol. Green is the safe-by-comparison gas color.

Poison gas is white with a skull (2.3)

A toxic or poison gas is Division 2.3. Its placard is white with a skull and crossbones and a 2. The skull is the warning that the gas is dangerous to breathe, so do not let the shared class number fool you into reading it as a plain compressed gas.

How to tell them apart

Read the color and symbol, not just the class number. Green and no skull means 2.2 non-flammable gas; white with a skull means 2.3 toxic gas. Confirm specifics against your official manual or the 49 CFR tables.

Frequently asked questions

What color is a non-flammable gas placard?
Green, with a 2 at the bottom, for Division 2.2 non-flammable, non-toxic gases. Verify with your official manual.
What does a poison gas placard look like?
Division 2.3 toxic gas uses a white placard with a skull and crossbones and a 2. The skull is the key difference from a plain compressed gas.
Are green gas and poison gas the same class?
Both are Class 2, but different divisions: 2.2 non-flammable gas (green) versus 2.3 toxic gas (white with skull). The color and symbol tell them apart.

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