Class 7 materials are known for being what?

Class 7 materials are classified as radioactive substances, which is consistent with the correct answer. Radioactive materials emit radiation and can pose significant health risks due to their unstable atomic nuclei that decay and release radiation. This type of classification is vital, especially in the context of transport and handling regulations, as these materials require specific safety measures to protect public health and the environment from potential exposure.

The other classifications pertain to different material hazards; flammable liquids are associated with igniting easily, corrosive substances can damage or destroy living tissue and materials upon contact, and explosive materials can cause blasts when subjected to heat, shock, or friction. Each class has its specific characteristics, but for Class 7, the defining property is its radioactivity. Understanding these classifications is essential for law enforcement and safety professionals in managing risks associated with hazardous materials.