When encountering unknown substances, what is the first priority of a first responder?

The first priority of a first responder when encountering unknown substances is the safety and health of themselves and the public. This principle is foundational in emergency response situations, as it ensures that responders do not put themselves or others at unnecessary risk.

In hazardous materials incidents, responders must assess the situation to determine potential immediate dangers presented by the substance, the environment, and any people in the vicinity. Prioritizing safety allows responders to take the necessary precautions and measures, such as establishing a safe perimeter, using Personal Protective Equipment (PPE), and communicating effectively with those affected.

While containment, evacuation, and identification of the substance are important steps, they should not be attempted until the safety of the responders and the public is ensured. By focusing first on safety, responders can prevent further harm and manage the situation more effectively.