Identify one major category of hazardous materials.

One major category of hazardous materials is flammable materials. Flammable materials are substances that can easily ignite and catch fire when exposed to an open flame, spark, or high temperatures. This category includes various liquids, solids, and gases that pose significant fire hazards and require special handling, storage, and transport protocols to prevent accidents. Understanding flammable materials' properties is crucial for safety in environments where these substances are present, such as in industrial or laboratory settings.

While inorganic materials, combustible materials, and non-toxic materials each represent different classes of substances, they do not all necessarily fall under the hazardous materials umbrella. Inorganic materials can include non-flammable substances, combustible materials are a broader classification that can include both flammable and non-flammable substances, and non-toxic materials are specifically those that do not pose a health risk. Flammable materials, however, are explicitly recognized for their dangerous fire-related characteristics, making them a clear example of hazardous materials.