What is the immediate action if a hazmat container starts venting, with risk of exposure?

Answer: B — Establish an exclusion zone, evacuate, and call HazMat; do not attempt to collect samples without PPE.

When a hazmat container starts venting, the priority is to protect people by creating distance and getting trained help on scene. Venting can release toxic, corrosive, or flammable vapors that pose inhalation or contact hazards, so you keep everyone out of the danger zone and establish an exclusion area. Evacuating nearby workers and bystanders prevents exposure, and calling HazMat ensures responders bring the right PPE, detection equipment, and containment and decontamination procedures to manage the release safely. Sampling or attempting to identify the substance on site is unsafe without proper protective gear and procedures, and improvising closure with makeshift materials can trap pressure, worsen the release, or create new hazards. Ignoring the situation isn’t an option—the safest path is to keep people away and bring in trained responders to handle the incident.