What Hazard Class is used to label a substance that readily yields oxygen to support combustion of fuels?

Answer: A — 5.

The designation for a substance that readily yields oxygen to support the combustion of fuels falls under Hazard Class 5, which is categorized as oxidizing substances. These materials can enhance or accelerate the flames of a fire, making them particularly dangerous in the presence of combustible materials. For example, certain oxidizers can cause explosive reactions when they contact organic materials or other fuels. They are critical to identify and manage accordingly in hazardous situations, as they can greatly increase the risk and severity of fire incidents. Having a clear understanding of this class is essential for effective hazard recognition and response in emergency situations.