What defines a contaminant in the context of hazardous materials?

In the context of hazardous materials, a contaminant is defined as a risk of direct injury or exposure. This definition encompasses substances that can present hazards to human health, the environment, or property. Contaminants can arise from various sources, including chemical spills, biological agents, or radiological materials, and their presence often requires specific safety measures to manage the associated risks.

Understanding contaminants as risks helps in formulating appropriate responses and safety protocols during incidents involving hazardous materials. For example, recognizing the potential for exposure to a contaminant drives the need for protective equipment and decontamination procedures to ensure the safety of individuals and mitigate environmental damage.

In contrast, the other options do not accurately define a contaminant. A physical hazard refers to types of hazards that can cause harm, but this does not encompass the entirety of what a contaminant may be. Describing a substance as harmless or as a decontamination agent does not align with the definition of a contaminant, which inherently suggests a level of risk or danger.