A reference book intended to be carried in every emergency vehicle in the United States.

• A. Hazardous Materials Handbook
• B. Chemical Safety Manual
• C. Incident Response Protocol
• D. Emergency Response Guidebook (ERG)

Answer: (D)

The main idea being tested is recognizing the standard field reference that every hazmat responder carries for quick on-scene guidance. The Emergency Response Guidebook is designed specifically for first responders to hazmat incidents, providing fast, practical information to identify unknown substances and decide initial actions before more detailed resources are available.

Why this is the best choice: it’s organized for rapid use when you’re at an incident scene. You can look up a material by its guide number or by its name, find the associated hazards, and immediately see recommended initial actions such as isolation distances, protective actions, and how to avoid ignition sources. It also points you to further help if needed (like CHEMTREC) and gives clear emergency response information suitable for the early response phase. This makes it the portable, universally used reference on emergency vehicles across the United States.

The other options don’t fit because they aren’t the standard on-scene reference for hazmat responses. They are more general or lab-oriented manuals and aren’t designed for quick field use, whereas the ERG is specifically built for rapid decision-making during the first minutes of an incident.