If a first responder encounters an unknown material at a scene, what is their first course of action?

When a first responder encounters an unknown material at a scene, establishing a safety perimeter is a critical first course of action. This step is essential for ensuring the safety of both the responder and any bystanders. By creating a perimeter, the responder can prevent unauthorized individuals from entering the hazardous area and mitigate the risk of exposure to the unknown material.

This action allows the responder to assess the situation more safely while waiting for specialized teams, such as hazardous materials (hazmat) units, to arrive. A safety perimeter serves as a buffer zone that protects the public and responders from potential harm, especially if the material may be toxic, flammable, or otherwise dangerous.

Other actions, such as attempting to contain the material or analyze it on-site, could expose the responder to unnecessary risks and should only be performed by trained personnel equipped for those tasks. Eating a snack and waiting for help is not a practical response to a potentially hazardous situation and does not contribute to the safety or management of the incident.