What are the two primary types of hazardous materials?

The two primary types of hazardous materials are flammable and toxic substances. Flammable substances are those that can easily ignite and burn, posing a fire hazard. This includes a wide range of materials, including gases, liquids, and solids that can catch fire when exposed to an ignition source. Toxic substances, on the other hand, are harmful or fatal when they enter the body, whether through inhalation, ingestion, or skin contact. The impact of toxic materials can range from mild health effects to severe or lethal consequences.

In contrast, while corrosive substances can indeed be hazardous by damaging living tissue or materials, they do not encompass the broader categories that include the commonly recognized risks posed by both flammable and toxic materials. Inert substances, while not typically classified as hazardous, do not fit into the primary classifications of materials that responders would focus on in hazardous materials situations. Therefore, the combination of flammable and toxic substances captures the critical aspects of threats that hazardous materials can present to safety and health.