Which publication is used to determine initial isolation and downwind distances during hazmat incidents?

• A. Calculates annual pesticide usage
• B. Provides isolation and downwind protection distances
• C. Lists all chemical names alphabetically
• D. Sets OSHA permissible exposure limits

Answer: (C)

Responders rely on the Emergency Response Guidebook to determine initial isolation and downwind protective action distances. The ERG translates a hazmat release into practical actions, listing the recommended isolation zone and how far downwind to expect hazardous concentrations, guiding evacuation or shelter-in-place decisions in the early moments of an incident. Other publications don’t provide those immediate protective-action distances: calculating pesticide usage isn’t about incident response distances, alphabetical chemical listings don’t offer protection guidance, and OSHA exposure limits govern workplace exposure rather than initial hazmat distances.