What does a compressed gas that is non-flammable and non-toxic have as a symbol?

• A. Green colored diamond with a white cylindrical tube
• B. A blue colored diamond with flames
• C. White diamond with a skull and crossbones
• D. White diamond with flames and vertical red stripes

Answer: (A)

The key idea here is that a compressed gas is identified by a cylinder symbol, which warns that the container is under pressure. Even if the gas itself isn’t flammable or toxic, the pressure can pose a danger if the container is heated, damaged, or mishandled. So the symbol shows a gas cylinder to indicate “gas under pressure” without implying flammability or toxicity.

That’s why the green diamond with a white cylindrical tube is the best choice: it communicates the presence of a compressed gas. The other options depict flames (flammable), a skull and crossbones (toxic), or flames with stripes (a different hazard), which aren’t appropriate for a non-flammable, non-toxic compressed gas.