Emergency Response Guidebook (ERG)

What Is Emergency Response Guidebook (ERG)?

The Emergency Response Guidebook (ERG) is a reference book published by the DOT (Department of Transportation) every two years, available in pocket-sized paper format and as a mobile app, that provides first responders with immediate information on hazardous materials identified by UN number, chemical name, or hazard class. The ERG lists isolation distances (how far to evacuate before entry personnel even approach), initial isolation zones and protective action zones (determined by wind direction and substance type), recommended PPE for responders, potential hazards (fire, explosion, toxic gas release), and basic suppression approaches. It also includes the ID numbers table (white pages, organized by UN number), the hazard class table (yellow pages, organized by hazard category), the chemical name table (blue pages, alphabetical), and reference pages (green) with isolation distance tables and first-aid guidance.

Why Emergency Response Guidebook (ERG) Matters on the Fireground

At a hazmat incident, the first thing responders do after identifying the substance (from placards, shipping papers, or the caller) is look up that substance in the ERG to find isolation zones and evacuation distances — getting this wrong by even a few blocks can mean the difference between evacuating enough people and having contamination spread beyond the established perimeter. The ERG is the fastest, most portable way to make that decision on-scene without waiting for a hazmat specialist or detailed reference library.

Relevant NFPA Standards

• NFPA 470: Hazardous Materials/Weapons of Mass Destruction (WMD) Standard for Responders
• DOT ERG 2024: Emergency Response Guidebook for First Responders

Field Procedures & Tactical Steps

1. Identify the hazardous substance via placards, shipping papers, labels, or caller description — obtain the UN number if visible, or the chemical name.
2. Open the ERG and go to the yellow pages (hazard class index) or blue pages (alphabetical chemical name index) to find the substance — the page will reference you to a numbered guide (e.g., Guide 128).
3. Turn to the referenced guide page, which shows the substance name, potential hazards (fire risk, toxic release, reactivity), initial isolation distances, and evacuation/protective action zones based on wind direction and time of day.
4. Read the isolation distance table on the green reference pages at the back if the guide references wind-dependent zones — these tables account for substance type and quantity to determine evacuation radius.
5. Communicate the isolation zone and evacuation distance to incident command and the dispatcher so evacuation boundaries are set and entry personnel know the hot zone perimeter before operations begin.

Common Context & Application

Every fire engine and ambulance in the US carries an ERG — usually a pocket-sized paper version in the jump kit or mounted in the apparatus. Dispatchers and first-in crews reference the ERG immediately upon identifying a hazmat incident, sometimes even before the hazmat team arrives, to establish initial evacuation zones and entry decisions.

Frequently Asked Questions about Emergency Response Guidebook (ERG)