HAZMAT CDL Practice Test 2025 - Free CDL Practice Questions and Study Guide

Hazard Class 2.1 specifically covers flammable gases. This classification is part of the United Nations system for identifying different types of hazardous materials and helps ensure that proper safety measures are taken during transport and handling. Flammable gases are those that can ignite and burn when mixed with air. They pose a significant risk due to their ability to form explosive mixtures and their potential to ignite from sparks or heat sources.

Other options refer to different types of hazardous materials that fall under different hazard classifications. For example, poisonous gases generally fall under Hazard Class 2.3, which addresses toxic gases. Non-flammable gases are categorized under Hazard Class 2.2, which includes gases that do not burn but can still pose other risks. Compressed air is often not classified under any hazard class as it is typically considered non-hazardous, depending on the context and presence of contaminants. Understanding these classifications helps in recognizing the proper safety protocols needed for handling and transporting hazardous materials.