What is the best practice for securing a hazardous materials area during an incident?

Establishing a perimeter with personnel is considered the best practice for securing a hazardous materials area during an incident because it ensures that trained responders can effectively control access to the scene. This method allows for monitoring of who enters and exits the area, reducing the risk of unauthorized access that could lead to further contamination or danger. Personnel can also provide immediate information and direction to individuals approaching the site, which is crucial in maintaining safety.

Utilizing a defined perimeter adds an extra layer of security, as it helps keep bystanders and uninformed personnel at a safe distance. This control is essential in hazardous situations, where exposure to dangerous materials can have serious health impacts. Having trained personnel on site is vital, as they can assess the conditions and changes that may occur during the incident, respond appropriately to any developments, and maintain communication with incident command.

While the other options may assist in securing the area to some extent, they do not provide the comprehensive security and control that personnel can offer. For example, using barricades alone lacks active monitoring, while a single entry point can limit access but still doesn't prevent the potential for unwanted entry. Visual barriers can obscure the view but do not actively enforce security or control access to potentially dangerous areas.