Free lesson · 2 min read · Updated 2026-10-25
How to Use the DOT Emergency Response Guidebook (ERG)
The Emergency Response Guidebook (ERG) is published by the U.S. Department of Transportation's Pipeline and Hazardous Materials Safety Administration with Transport Canada and Mexico's transportation agency. It is written for first responders in the first 30 minutes of a transportation incident involving hazardous materials, before more detailed information is available. HAZWOPER awareness-level responders are expected to know how to use it. A new edition comes out about every four years.
Step 1: identify the material
You need one of these, gathered from a safe distance, upwind and uphill:
- The 4-digit UN or NA identification number on a placard, orange panel or shipping paper
- The proper shipping name on shipping papers or package markings
- If nothing else, the placard itself (diamond shape, color and class number)
Never walk into a cloud, spill or fire to read a label. Binoculars help.
Step 2: find the guide number
| Section | Color | How it's organized |
|---|---|---|
| ID number index | Yellow-bordered pages | By 4-digit UN/NA number, giving the 3-digit guide number and name |
| Name index | Blue-bordered pages | Alphabetically by material name, giving the guide number and ID number |
| Guides | Orange-bordered pages | Numbered guides 111 to 174 with hazards and actions |
| Isolation and protective action distances | Green-bordered pages | Distances for highlighted toxic-by-inhalation and water-reactive materials |
If you only have a placard, the white pages at the front show placards with the guide to use. A guide number followed by the letter P means the material can polymerize violently when heated or contaminated.
Step 3: read the orange guide
Each orange guide has three parts:
- Potential hazards: fire or explosion, and health. The more important of the two is listed first.
- Public safety: who to call, an immediate isolation distance in all directions, protective clothing and evacuation advice.
- Emergency response: fire, spill or leak, and first aid actions.
Step 4: check for highlighted materials
Entries highlighted in the yellow and blue pages are toxic inhalation hazard (TIH) materials, chemical warfare agents, or materials that give off toxic gas when spilled in water. For these, go to the green pages:
- Initial isolation zone: a circle around the spill where people may be exposed to dangerous concentrations upwind and downwind
- Protective action zone: an area downwind where people should be evacuated or sheltered in place, with separate day and night distances. Night distances are often larger because the air is more stable
- Small spills and large spills have different distances
If a highlighted material is on fire, use the evacuation distance in the orange guide's public safety section instead, because fire changes how the material spreads.
Hazard classes on placards
- Explosives
- Gases (flammable, non-flammable, toxic)
- Flammable liquids
- Flammable solids, spontaneously combustible and dangerous-when-wet materials
- Oxidizers and organic peroxides
- Toxic and infectious substances
- Radioactive materials
- Corrosives
- Miscellaneous hazardous materials
What awareness-level responders do next
Under HAZWOPER paragraph (q)(6)(i), awareness-level responders recognize the release, identify the material if they can, isolate the area, make notifications and then stay out of it. Containing or stopping the release takes operations or technician training. Practice with the ERG quiz.
Frequently asked questions
What do the colored pages in the ERG mean?
Yellow pages list materials by ID number, blue pages list them by name, orange pages are the response guides, and green pages give isolation and protective action distances for highlighted materials.
What does a highlighted entry in the ERG mean?
It is a toxic inhalation hazard material, a chemical warfare agent, or a material that releases toxic gas in water. Use the green pages for isolation and protective action distances unless it is on fire.
What does the letter P after a guide number mean?
The material may polymerize violently when heated or contaminated.
This guide summarizes federal OSHA, Cal/OSHA and EPA rules for training purposes. It is not legal advice. Always check the current regulation text and your site safety and health plan.