Question 818 Deck General

The correct answer is D) Flammable gases. According to the U.S. Department of Transportation's Hazardous Materials Regulations, a Class 2.1 substance is classified as a "Flammable gas". This includes gases that are flammable under normal conditions and pressure, and pose a risk of fire or explosion. The proper label name for a Class 2.1 substance is "Flammable gases". The other options are incorrect because: A) "Non-flammable gases" refers to Class 2.2 substances, B) "Toxic gases" refers to Class 2.3 substances, and C) "Inert gases" are a subset of non-flammable gases and do not fall under the Class 2.1 classification.