Which of the following is not considered a critical HAZMAT category?

In hazardous material management, HAZMAT categories are established to define the severity and the degree of risk associated with certain types of materials. Each category corresponds to specific regulations, handling instructions, and safety measures necessary to mitigate risks. Categories are generally ranked from most to least critical based on the potential impact on health and safety in the event of exposure or mishandling.

Category 1 is typically recognized as the most critical, including materials that can cause severe health effects or even fatalities upon exposure. Category 2 includes materials that pose significant health risks but may have additional controls or mitigations in place. Category 3 generally represents materials that are of lower risk compared to the first two categories.

Category 4 generally includes materials that are considered non-hazardous or pose minimal risk. As such, these materials require less stringent handling protocols and are not classified as critical in the same way that categories 1, 2, and 3 are. Thus, C is the correct answer, as it reflects a classification that does not indicate a material's critical hazardous nature.