# ERG2024 Summary of Changes

**Citation:** ERG 2024 Summary of Changes  
**Type / status:** guidance / guidance  
**Agency:** Pipeline and Hazardous Materials Safety Administration  
**Effective:** Not stated  
**Published:** 2024-03-11

Official PHMSA summary of major changes from ERG2020 to ERG2024.

## Document text

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SUMMARY OF CHANGES:
ERG2024
Major changes from the 2020 edition of the Emergency Response
Guidebook (ERG)
PHMSA | PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION
1

Disclaimer: This list is not exhaustive and should not be treated as a replacement for the ERG. In an
emergency, be sure to consult the ERG2024 for accurate response guidance.

We have compiled the most important changes from ERG2020 to ERG2024, organized by the color of
the corresponding section in the guidebook-White, Yellow/Blue, Orange, and Green. In addition to
the changes listed below, all sections have undergone minor editorial changes for accuracy
and consistency.
In this edition, we have added QR codes to the back cover of the hard copy version of ERG2024,
offering quick access to critical incident reporting information for users on the scene of an emergency.
WHITE SECTION
FRONT MATERIAL
MIDDLE MATERIAL
• Updated the Table of Markings, Labels, and Placards
• Added a table to help in deciding whether Evacuation
to remove (2) obsolete designs: triangular Marine
or Shelter-in-Place is the best option.
Pollutant marking and yellow Division 5.2 placard
• Updated the Road Trailer Identification Chart
to include new descriptive text on some of the
configurations/types.
• Updated the Rail Car Identification Chart by adding a
cryogenic railcar.
END MATERIAL
• Added Liquid Spill Control methods section, including guidance
Expanded glossary, includes:
on the types and uses of absorbent materials.
• Added Considerations for Lithium Battery and Electric Vehicle
• Air-reactive
(EV) Fires, including identification of Damaged, Defective or
• Combustible
Recalled (DDR) lithium batteries.
• Control temperature
• Removed Chemical and Biological Warfare
Agents considerations.
• Criticality Safety Index (CSI)
• Added a new Chemical and Biological Warfare Agents section
Evacuate
in the Criminal or Terrorist Use of Chemical, Biological and
• Isolate
Radiological Agents section. All Chemical and Biological
Warfare Agents considerations that were found throughout the
• Polar
ERG are now collected in this new section. Chemical Warfare
• Self-heating material
Agents (CWA) are now listed based on their type and symptoms,
not by their name. This new section includes:
• Self-reactive material
• Biological Warfare Agents table
• Spontaneously
combustible material
• Chemical Warfare Agents table
• Thermal runaway
• Initial Isolation and Protective Action Distances for CWA.
• Water insoluble
• Water soluble
• Clarified differentiation of Solid or
Straight Stream.
PHMSA | PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION

YELLOW AND BLUE SECTIONS
Added eleven (11) new UN numbers listed in the UN Model
Recommendations on the Transport of Dangerous Goods
(up to the 23rd revised edition) and assigned
Orange guides:
Re-evaluated materials to make sure that they are assigned
to the appropriate Orange guide. Moved nineteen (19)
materials to a different guide:
ID No. Guide No.
ID No. ERG2020 ERG2024
UN3550 151
UN1541 155 156
UN3551 147
UN1545 155 131
UN3552 147
UN1570 152 151
UN3553 116
UN1728 155 156
UN3554 172
UN1815 132 155
UN3555 113
UN1866 127 128
UN3556 147
UN2206 155 156
UN3557 138
UN2285 156 155
UN3558 147
UN2295 155 131
UN3559 171
UN2299 155 156
UN3560 153
UN2353 132 155
UN2395 132 155
UN2474 157 156
UN2643 155 153
UN2751 155 156
UN2947 155 127
UN3172 153 152
UN3293 152 153
UN3462 153 152
4

YELLOW AND BLUE SECTIONS (cont'b)
• Removed the following UN numbers that are obsolete:
• UN1014 - Carbon dioxide and oxygen mixture, compressed
• UN1015 - Carbon dioxide and nitrous oxide mixture
• UN1366 - Diethylzinc
• UN1370 - Dimethylzinc
• UN2005 - Magnesium diphenyl
• UN3051 - Aluminum alkyls
• UN3053 - Magnesium alkyls
• UN3076 - Aluminum alkyl hydrides.
• Removed the Chemical Warfare Agents from the Yellow and Blue Sections (incorporated into the Criminal or Terrorist
Use of Chemical, Biological and Radiological Agents section).
• Added the polymerization hazard (P) to UN3302 - 2-Dimethylaminoethyl acrylate, Stabilized.
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PHMSA I PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION

ORANGE SECTION
•
•
Moved the general first aid recommendations to a new section called “General First Aid” (found before Guide 111)—
kept only material-specific recommendations in Orange Guide pages.
Added the following recommendations in the Guides:
Guide No. CHANGE
115 Added caution statement for liquefied natural gas (LNG) released on/near water,
product may vaporize explosively.
118, 136 Added reference to Table 1 for highlighted materials.
128, 130 Added alcohol-resistant foam to fire response guidance.
131 Added Potential Health Hazard: "Methyl chloroacetate (UN2295) is an eye irritant/
lachrymator (causes flow of tears)."
138, 159 Removed reference to Table 1.
140 Expanded guidance for ammonium nitrate products.
147 Revised firefighting recommendations for lithium-ion battery fires, and added
guidance for electric vehicle (EV) fires. Now includes sodium-ion batteries.
151 Added response guidance for spills of solid materials.
153 Added Potential Health Hazard: “Methyl bromoacetate (UN2643) is an eye irritant/
lachrymator (causes flow of tears).”
156 Additional Response guidance: “For Acetyl bromide (UN1716), use CO2 or dry
chemical only.”
166 Added Potential Health Hazard: “Toxic; may be fatal if inhaled, ingested, or
absorbed through skin.” Revised Large Fire response guidance.
171 Added caution statement for delayed activation and projectile risk of Safety devices
(UN3268) and Fire suppressant dispersing devices (UN3559).
6

GREEN SECTION
•
•
Table 1:
| Chemical warfare agents removed, incorporated into the Criminal or Terrorist Use of Chemical, Biological and
Radiological Agents section
| Revised the distances
| No new entries resulting from new UN numbers.
Table 3:
| Revised distances.
ERG2024 MOBILE APPS
The ERG2024 is also available as a mobile application, for both iOS and Android devices, in English, French, and Spanish!
NEW TO THE ERG APP?
To download the app, use the QR code (below) which corresponds to your device, or you can locate the app by name in
either the App Store (iOS) or Google Play (Android).
ERG FOR iOS
ERG2024 FOR ANDROID
ALREADY HAVE THE APP?
If you have already downloaded ERG for iOS or ERG2020 for Android, published by the Pipeline
and Hazardous Materials Safety Administration (PHMSA), no action needed! Your app will update
automatically to ERG2024.
For more ERG resources, visit PHMSA’s Emergency Response Guidebook (ERG) webpage:
https://www.phmsa.dot.gov/training/hazmat/erg/emergency-response-guidebook-erg
First responders, we want your feedback! Submit your name, organization, contact information,
and comments to ERGComments@dot.gov
PHMSA | PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION
7

For additional information contact:
The Hazardous Materials Info Center
1-800-HMR-4922
(1-800-467-4922)
Email: infocntr@dot.gov
Pipeline and Hazardous Materials
Safety Administration
Outreach, Training, and Grants Division
East Building, 2nd Floor
1200 New Jersey Ave., SE
Washington, DC 20590
Email: training@dot.gov
202-366-4900
202-366-7342 (Fax)
PHH50-0207-0224

## Provenance

- Official: Yes
- Source: <https://www.phmsa.dot.gov/training/hazmat/erg/erg2024-summary-changes>
- Source ID: `phmsa-erg-2024`
- SHA-256: `b84f229d3f86a92a15f5581760ae2cb5c970ad99cb4e7fe0b5167144b98739f4`
- Retrieved: 2026-08-13T11:31:32.574Z
- Exported: 2026-08-24T03:29:59.391Z
- Document slug: `phmsa-erg-2024-summary-of-changes`

### Source metadata

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  "caveat": "This summary is not exhaustive and is not a replacement for ERG2024. Consult the current guidebook for emergency-response guidance.",
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  "collectionId": "phmsa-erg-2024-overview",
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  "sourceDateLabel": "Effective Date",
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```