Summary of changes from ERG2020 to ERG2024

We have listed the most important changes from ERG2020 to ERG2024. They’re organized based on the color of the corresponding section in the guidebook—White, Yellow/Blue, Orange, and Green. In addition to the changes below, all sections have received minor editorial changes for accuracy and consistency.

In this edition, QR codes have been added to the back cover of the hard copy version of ERG2024 to provide more rapid access to critical services while users are on-scene.

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

White section

  • Table of Markings, Labels, and Placards: Removed two (2) obsolete designs: triangular Marine 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 rail car.
  • Added table to help decide whether Evacuation or Shelter-in-Place is best option.
  • Added Liquid Spill Control methods subsection, including guidance on types and uses of absorbent materials.
  • Added Considerations for Lithium Battery and Electric Vehicle (EV) Fires, including identification of damaged, defective and recalled (DDR) lithium batteries.
  • Added a new Chemical and Biological Warfare Agents subsection in the “Criminal or Terrorist Use of Chemical, Biological and Radiological Agents” section. All Chemical and Biological Warfare Agents considerations that were found throughout the ERG are now collected in this new subsection. Chemical Warfare Agents (CWA) are now listed based on their type and symptoms, not by their name. This new subsection includes:
    • Biological Warfare Agents table
    • Chemical Warfare Agents table
    • Initial Isolation and Protective Action Distances for CWA.
  • Expanded glossary, includes:
    • Air-reactive
    • Combustible
    • Control temperature
    • Criticality Safety Index (CSI)
    • Evacuate
    • Polar
    • Self-heating material
    • Self-reactive material
    • Spontaneously combustible material
    • Thermal runaway
    • Water insoluble
    • Water soluble
    • Clarified differentiation of Solid or Straight Stream.

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:

    ID No. Guide No.
    UN3550 Guide 151
    UN3551 Guide 147
    UN3552 Guide 147
    UN3553 Guide 116
    UN3554 Guide 172
    UN3555 Guide 113
    UN3556 Guide 147
    UN3557 Guide 138
    UN3558 Guide 147
    UN3559 Guide 171
    UN3560 Guide 153
  • 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. ERG2020 ERG2024
    UN1541 155 156
    UN1545 155 131
    UN1570 152 151
    UN1728 155 156
    UN1815 132 155
    UN1866 127 128
    UN2206 155 156
    UN2285 156 155
    UN2295 155 131
    UN2299 155 156
    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
  • 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”).
  • Added the polymerization hazard (P) to UN3302 2-Dimethylaminoethyl acrylate, Stabilized.

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 the Orange guides.
  • Added the following recommendations in the guides:

    Guide(s) 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).

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

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