Which of the following is NOT a primary route of exposure to hazardous materials?

The correct choice identifies radiation as not being a primary route of exposure to hazardous materials in the context typically covered in hazardous materials safety training. The primary routes of exposure to hazardous materials generally include inhalation, ingestion, and skin contact.

Inhalation refers to breathing in harmful chemicals or particles, making it one of the most common routes of exposure, especially in industrial or chemical spill situations. Ingestion involves the swallowing of substances, which can happen accidentally or through contaminated food or drink. Skin contact is another significant route, as many hazardous materials can penetrate the skin and enter the bloodstream.

Radiation, while dangerous and potentially harmful, is primarily classified under a different category of exposure. It often involves different protocols and safety measures compared to chemical exposure routes. Hence, this distinction clarifies why radiation is not recognized as a primary route of exposure to hazardous materials in the same context as inhalation, ingestion, and skin contact.