Hazmat Emergencies and the ERG
Updated October 27, 2026
The emergencies part of the CDL hazmat test asks what a driver should do, and not do, when something goes wrong: a crash, a fire, a leak. It also covers the Emergency Response Guidebook and which incidents must be reported. These answers follow the CDL manual and 49 CFR 171.15 and 171.16.
The Emergency Response Guidebook (ERG)
The ERG is published by the U.S. Department of Transportation for firefighters, police and industry workers. It tells them how to protect themselves and the public in the first phase of a hazmat incident. It is indexed by proper shipping name and identification number, which responders find on your shipping papers and placards. That is why those have to be right.
| ERG section | What it holds |
|---|---|
| Yellow-bordered pages | Materials listed by ID number |
| Blue-bordered pages | Materials listed alphabetically by name |
| Orange-bordered pages | The response guides |
| Green-bordered pages | Initial isolation and protective action distances for toxic inhalation hazard materials |
At a crash
Your job is to keep people away, limit the spread of the material only if you can do it safely, tell responders about the danger and give them the shipping papers and emergency response information.
- Check that your driving partner is OK.
- Keep the shipping papers with you.
- Keep people far away and upwind.
- Warn others of the danger.
- Call for help.
- Follow your employer’s instructions.
Fires
- You may use your extinguisher on a minor truck fire, such as a tire fire, to keep it from reaching the cargo.
- Do not fight a hazmat cargo fire unless you have the training and protective equipment for it.
- Feel the trailer doors before opening them. If they are hot, leave them closed: fresh air can make the fire flare up.
Leaks
- Identify the material from the shipping papers, labels or the package’s location. Never touch it, and never try to identify it by smell.
- Do not eat, drink or smoke near a leak or spill.
- Move the vehicle only as far as safety requires, such as off the road and away from people. Never keep driving to find a phone or help.
- If material is spilling: park, secure the area, stay there, and call or send someone for help.
- Give the person you send a written note with the emergency, your exact location and direction of travel, your name, the carrier’s name and terminal city, and the material’s shipping name, hazard class and ID number if you know them.
- Do not repack or repair a leak unless you have the training and equipment.
Reporting
Call the National Response Center at 800-424-8802 (24 hours) as soon as practical, and no later than 12 hours, when a hazmat incident directly causes any of these:
- a person is killed;
- a person is injured and admitted to a hospital;
- the general public is evacuated for one hour or more;
- a major transportation artery or facility is closed for one hour or more;
- fire, breakage, spillage or suspected contamination involving radioactive material or an infectious substance;
- a release of a marine pollutant over 119 gallons (liquid) or 882 pounds (solid); or
- any situation the carrier judges should be reported, such as a continuing danger to life.
The carrier must also file a detailed written incident report within 30 days. CHEMTREC (800-424-9300) is another 24-hour line, run by industry, that gives responders technical information about chemicals.
Test yourself
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Who publishes the Emergency Response Guidebook used in the United States?Answer: AThe ERG is a U.S. Department of Transportation guidebook for emergency responders. Motor carriers often keep one in each vehicle that hauls hazmat.
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You know a material's four-digit ID number. Which ERG pages list materials in ID number order?Answer: BThe yellow-bordered pages list materials by ID number and the blue-bordered pages list them by name. Both point you to a response guide in the orange pages.
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A package in your trailer is leaking an unknown liquid. Which action is wrong?Answer: CNever try to identify a leak by smell. Some toxic gases can harm you or deaden your sense of smell even when you notice no odor.
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Hazmat is spilling from your truck at a rest area with no phone nearby. Which plan follows the manual?Answer: DDo not drive on with a leak to find help. Park, secure the area, stay there, and call or send someone for help with the details written down.
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A tire on your placarded trailer catches fire before it reaches the cargo. What may you do?Answer: AYou may fight a minor truck fire, such as a tire fire, to keep it from reaching the cargo. Do not fight a hazmat cargo fire without special training and equipment.
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Which of these must be phoned in to the National Response Center?Answer: BPhone notice is required when, as a direct result of the hazardous material, the general public is evacuated for one hour or more, among other triggers such as a death or a hospital admission.
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What is the National Response Center's 24-hour phone number?Answer: CThe National Response Center's toll-free line is 800-424-8802. 800-424-9300 is CHEMTREC, a separate industry line that shares information with the National Response Center.
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What does CHEMTREC provide?Answer: DCHEMTREC runs a 24-hour line that gives emergency personnel technical information about the physical properties of hazardous materials.
See also: hazmat driving rules and the CDL hazmat practice test.
Pass your hazmat endorsement test on the first try
- All 181 questions on hazard classes, shipping papers, placards, loading, cargo tanks, driving and parking rules and emergencies
- An explanation for every answer, from the CDL manual and the federal hazmat rules
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