Which of the following is NOT considered a category of hazardous materials?

Household items typically not classified as HAZMAT are indeed recognized as a category that does not fall under the strict definitions of hazardous materials. This classification is based on the fact that certain household items, although they may contain chemicals or compounds, are used within a context that does not pose significant risks in terms of transportation or handling when compared to more strictly regulated materials.

On the other hand, categories such as explosives, radioactive materials, and toxic substances all represent substances that pose significant risks and are subject to stringent regulations and safety protocols to minimize potential harm to human health and the environment. Explosives can cause dangerous reactions under certain conditions, radioactive materials emit harmful radiation that can be deadly, and toxic substances can cause adverse health effects or environmental damage upon exposure. Thus, these categories are clearly classified as hazardous materials, while many common household products do not meet the criteria for such classification.