49 CFR 172.604: Emergency Response Telephone Number Requirements

When a covered hazardous material is offered for transportation in the United States, 49 CFR 172.604 generally requires a numeric emergency response telephone number on the shipping paper. The number must be monitored while the material is in transportation, including storage incidental to transportation, and provide immediate access to knowledgeable emergency response information.

Key Takeaway

Under 49 CFR 172.604, hazmat emergency phone number requirements include using a complete numeric number, placing it correctly on the shipping paper, and monitoring it throughout transportation. The person answering must know the material and have comprehensive emergency response and incident-mitigation information—or have immediate access to someone who does. A callback-only system does not meet the requirement.

Related 2026 update: Effective September 3, 2026, PHMSA’s HM-268D final rule allows domestic carriers and applicable facility operators to maintain emergency response information required by § 172.602 in either hard copy or electronic format. This does not change the § 172.604 emergency telephone number requirements.

What Does 49 CFR 172.604 Require?

A Complete, Monitored Number

The shipping paper must provide a numeric telephone number with the appropriate area code. A number outside the United States must include the international access information and applicable country and city codes needed to place the call.

The number must be monitored whenever the hazardous material is in transportation, including storage incidental to transportation. A business-hours-only line may not be sufficient when a shipment remains in transportation outside those hours.

Immediate Access to Knowledgeable Support

The number must reach someone who understands the hazardous material and has comprehensive emergency response and incident-mitigation information, or someone with immediate access to that knowledge.

Voicemail, an answering machine, a pager, or an answering service that requires a callback does not satisfy the requirement. Learn more about common hazmat hotline failures.

Where Must the Emergency Number Appear?

The emergency response telephone number must appear on the shipping paper either:

• Immediately after the hazardous material description to which it applies; or
• Once in a prominent, readily identifiable location when it applies to every hazardous material listed.

When the number appears only once, it must be clearly identified as an emergency response number.

Who Is Responsible for the Number?

The person offering the hazardous material for transportation must provide the required number. A person preparing a shipping paper for continued transportation must also include it. If that person replaces the original emergency response number, they assume responsibility for meeting the requirements of 49 CFR 172.604.

Separately, 49 CFR 172.602(c) requires carriers to keep emergency response information accessible to transportation personnel and government emergency responders during transportation.

What Information Must Be Available?

PHMSA’s emergency response information guidance explains that the information must be current, accurate, and consistent with the material being transported. It must include the basic description and technical name, when required, and address:

• Immediate health hazards
• Fire or explosion risks
• Immediate incident precautions
• Initial methods for handling fires
• Initial methods for handling spills or leaks
• Preliminary first-aid measures

The information may appear on the shipping paper, an associated document such as a Safety Data Sheet, or a recognized emergency response guide that can be cross-referenced to the shipping description.

Effective September 3, 2026, § 172.602(b)(1) allows domestic carriers and applicable facility operators to maintain this emergency response information in either hard-copy or electronic format. If an electronic format is used, the information must still be immediately available. Loss of cellular service, device power, or device functionality does not relieve the responsible party of that requirement.

Can a Third-Party Emergency Response Provider Be Used?

Yes. The emergency response number may belong to the offeror or to an agency or organization capable of and accepting responsibility for providing the required information.

When an Emergency Response Information Provider is used, the registered person must be identified by company name, contract number, or another provider-assigned identifier. Unless the company name appears prominently elsewhere on the shipping paper, the identifier must appear immediately before, after, above, or below the emergency response number.

The registered company must also provide the provider with current information about the hazardous material before offering it for transportation.

When Does 49 CFR 172.604 Not Apply?

Section 172.604 includes specific exceptions, including materials properly offered under limited-quantity or excepted-quantity provisions, certain materials named in the regulation, and certain fumigated transport vehicles or freight containers when no other hazardous material is present.

Materials excepted from shipping-paper requirements are also not required to provide the emergency response information described in Subpart G. Applicability depends on the material, quantity, shipping description, mode, and other Hazardous Materials Regulations.

Effective September 3, 2026, PHMSA’s HM-268C final rule expands the quantities of qualifying lithium batteries that may be transported under the Materials of Trade exception in 49 CFR 173.6. Qualifying materials of trade are generally excepted from HMR requirements not specifically referenced in that section, which can affect whether § 172.604 applies.

Requirements outside the United States may differ. CHEMTREC’s Global Guide to Emergency Response Numbers provides an overview of international considerations.

Common Emergency Number Mistakes

• Using a line that is not monitored throughout transportation
• Relying on voicemail or a callback-only service
• Listing an incomplete, incorrect, or nonworking number
• Placing the number where it is difficult to find
• Omitting a required registered-company identifier
• Using a provider’s number without authorization
• Failing to provide current product information
• Relying on electronic emergency response information that may become inaccessible because of connectivity, power, or device limitations

These issues can delay access to important emergency response information and may lead to enforcement action.

How CHEMTREC Supports Registered Shippers

CHEMTREC is an Emergency Response Information Provider with a 24/7 Emergency Operations Center staffed by Emergency Services Specialists. CHEMTREC offers Inside Zone, Outside Zone, and Global Coverage based on shipment origins and destinations.

Learn more about what happens when you call a 24/7 hazmat emergency response line, from the initial assessment and hazard identification to protective guidance and response coordination.

Registration authorizes a company to display the applicable CHEMTREC emergency response telephone numbers. Registered companies also receive a unique CHEMTREC Customer Number, or CCN, which may be used to identify the company on shipping papers. When displayed, it is preceded by “CCN,” for example, CCN123456.

Only registered companies are authorized to use CHEMTREC’s emergency response telephone numbers. Registration can support compliance when the correct coverage, number, identifier, and current product information are used. Shippers remain responsible for determining which requirements apply.

Review Your Emergency Response Number Process

Before the next covered shipment moves, review your shipping papers, number placement, provider authorization, product information, and after-hours call handling.

If using electronic emergency response information, also confirm that it will remain immediately available during connectivity, power, or device disruptions.

Learn more about CHEMTREC’s Emergency Response Information Provider services, explore available coverage options, or request a quote. You can also call the CHEMTREC sales team at 1-800-262-8200, Monday through Friday, 8:00 a.m.–5:30 p.m. ET.