Toxic Gases are classified by what number identification/placard number?

• A. 2.3
• B. 1.0
• C. 3.2
• D. 6.1

Answer: (A)

Understanding hazmat placards: they encode hazard class and a subclass. For gases, the class is 2, and the subclass 3 identifies a poisonous or toxic gas. So a toxic gas carries the designation 2.3, signaling an inhalation and acute toxicity hazard that requires particular care, such as ventilation controls and appropriate respiratory protection. Other numbers point to different hazards—1.x are explosives, 3.2 refers to a subcategory of flammable liquids, and 6.1 covers toxic substances that aren’t gases. The 2.3 label specifically flags a toxic gas, making it the correct identification for toxic gases.