When should decontamination of exposed personnel begin?

• A. In the clean zone after decon
• B. Immediately after incident
• C. As soon as feasible at the hot/warm zone boundary, before personnel re-enter clean areas
• D. After all operations stop

Answer: (C)

Contamination control at hazmat scenes relies on decontaminating exposed personnel as they move out of the highly contaminated area. Decontamination should begin as soon as feasible at the boundary between the hot zone (where contamination is present) and the warm decon zone, and before anyone re-enters clean areas. Establishing this boundary allows contaminants to be removed early—often through rapid gross decon and PPE doffing—so they aren’t carried into areas that should remain uncontaminated, including medical treatment areas and equipment. Starting decon at this point minimizes secondary exposure and protects both responders and any exposed personnel as operations continue. Waiting until after the incident or after all operations stop would permit further spread of contamination and complicate subsequent cleanup.