How to Complete an IMO Dangerous Goods Declaration

To complete an IMO Dangerous Goods Declaration, use the IMO Multimodal Dangerous Goods Form, enter the shipper and consignee details, describe each hazardous substance in the exact sequence the IMDG Code requires (UN number, proper shipping name, hazard class, packing group, flashpoint where applicable, and marine pollutant status), record the quantities and container details, add a monitored 24-hour emergency response telephone number, and sign the shipper’s certification before submitting the document to the carrier ahead of the dangerous goods cutoff. The form itself is available from the International Maritime Organization.¹

When You Need a Declaration

A declaration is required for any packaged shipment of goods that fall within one or more of the nine IMDG hazard classes, from explosives (Class 1) through miscellaneous dangerous goods (Class 9). SOLAS Chapter VII makes the IMDG Code the binding standard for sea transport of packaged dangerous goods, covering classification, packaging, stowage, segregation, and documentation.² If your cargo fits any of those classifications, no carrier will accept it for loading without a completed declaration.

IMDG Code Amendment 42-24 became mandatory on January 1, 2026. Declarations must reflect the current edition’s requirements.

Working Through the Multimodal Form

Carrier-specific versions of the form exist and their box numbering can vary, but the data requirements are the same across all versions. Start at the top.

Box 1 identifies the shipper, consignor, or sender by full legal name and address. This is who bears legal responsibility for the accuracy of everything that follows. Fill in the consignee, freight forwarder, and vessel or voyage details in the corresponding boxes as the form directs.

Box 14 is where the dangerous goods description goes: shipping marks, plus the substance data in the sequence the IMDG Code prescribes.¹ Port authorities and vessel crews rely on that standardized order to locate critical safety data quickly, especially in an emergency, so this is not the place to freelance.

The Dangerous Goods Description, in Order

Chapter 5.4 of the IMDG Code specifies exactly what data must appear on the declaration. Each item drives a specific safety decision on the vessel.

UN Number. The four-digit identifier assigned to the specific substance (for example, UN1219 for isopropyl alcohol). This number drives every downstream safety decision, from stowage to emergency response.
Proper Shipping Name. The internationally recognized name from the IMDG Code’s Dangerous Goods List. Trade names and abbreviations are not acceptable.
Hazard Class and Division. The primary class (Class 3 for flammable liquids, Class 8 for corrosives, and so on) plus any subsidiary risks. Subsidiary hazards determine segregation. A Class 8 corrosive with a Class 3 subsidiary risk cannot be stowed next to oxidizers.
Packing Group. Packing Group I is the highest danger and requires the strongest packaging; Group II is medium; Group III is the lowest.
Flashpoint. Required for flammable liquids (Class 3). The crew uses it to set safe storage temperatures and ventilation.
Marine Pollutant status. If the substance qualifies as a marine pollutant, say so. That status triggers additional package marking and specific stowage rules.
Total quantity. Net and gross mass or volume per package, and the total for the consignment.
Container identification and seal numbers. For containerized shipments, the container ID and seal number create the chain of custody from packing to delivery.

The Shipper’s Certification and Signature

The Shipper’s Declaration sits as its own section of the form, not inside one of the numbered data boxes. It is the legally binding statement that the contents are “fully and accurately described” by the proper shipping name, and that the goods are classified, packed, marked, labeled, and “in all respects in proper condition for transport.”

The authorized representative signs in Box 22, along with the company name, the declarant’s name, and the place and date of signing.¹ That signature is where personal liability attaches. Most enforcement actions start with a signed declaration that turned out to be wrong.

Container or Vehicle Packing Certificate

For goods packed into freight containers or vehicles, a Container/Vehicle Packing Certificate is also required. It confirms that the goods were loaded and secured in compliance with the IMDG Code, that packages were inspected for damage before loading, and that incompatible substances were properly segregated inside the unit.¹ The packing certificate can appear on the same form as the DGD or as a separate document, depending on the carrier.

Emergency Response Telephone Number

For any shipment moving under U.S. federal regulations, the shipping paper must include a numeric emergency response telephone number with area code, monitored at all times the material is in transportation. The person answering must be knowledgeable about the specific hazardous material and have comprehensive emergency response information, or have immediate access to someone who does. Answering machines, answering services, and beepers do not satisfy the requirement.³

Many shippers contract with providers like CHEMTREC. If you use one, the contract number or unique identifier assigned by the provider must appear on the shipping paper next to the phone number.³ Omitting this number is one of the most frequently cited violations in hazmat enforcement.

Special Cases That Change What You Write

Limited Quantity Shipments

Dangerous goods shipped in small inner packages within combination packaging may qualify for limited quantity treatment under IMDG Code Chapter 3.4. Limited quantity shipments do not require hazard class labels or marine pollutant markings on the packages, and UN specification packaging is not mandatory. A shipper’s declaration is still required, and it must include the full shipping description along with the notation “Limited Quantity” or “LTD QTY.” Total gross mass of each package cannot exceed 30 kilograms.

Overpacks

When multiple packages are secured together in a single overpack, the word “OVERPACK” must appear on the outside if the individual package markings and labels are not visible from the exterior. The declaration should reflect the overpack arrangement and identify every dangerous good inside it. Where the safety marks on the inner packages are visible through or on the overpack, reproducing them on the exterior is generally not required.

Lithium Batteries

Lithium batteries are among the most commonly misdeclared dangerous goods. Lithium ion batteries fall under UN3480 (batteries alone) or UN3481 (packed with or contained in equipment). Lithium metal batteries fall under UN3090 or UN3091 in the same configurations. Packaging, labeling, and declaration requirements differ between each UN number and configuration, so the classification you enter has to match the exact physical arrangement.

PHMSA’s Lithium Battery Guide confirms that lithium batteries and battery-powered equipment may be transported by vessel within the United States under the IMDG Code, and recommends consulting the most recent edition. One current change worth flagging: the telephone number marking on lithium battery packages is being phased out, with a deadline of December 31, 2026.⁴ Verify current marking and documentation requirements against IMDG Code Amendment 42-24 for each battery type and shipping configuration before you sign.

U.S. Requirements Layered on Top

The United States authorizes use of the IMDG Code under 49 CFR 171.22, so U.S. shippers can prepare documentation under IMDG standards rather than converting to domestic 49 CFR format. Several domestic requirements still apply on top of the international standard:⁵

Emergency response information and 24-hour telephone number under 49 CFR Part 172, Subpart G.
Hazmat employee training under 49 CFR 172.704, including function-specific training on the IMDG Code if that is the standard being used.
Security plans under 49 CFR Part 172, Subpart I.
Incident reporting under 49 CFR 171.15 and 171.16.
English language on all shipping paper information and package markings. Dual-language documentation is permitted.
Shipper’s certification under 49 CFR 172.204, provided by the forwarding agent at the U.S. point of entry to the initial U.S. carrier.

Materials that are forbidden under 49 CFR 173.21 or the Hazardous Materials Table cannot be shipped under IMDG authorization, regardless of their international classification.⁵

Submitting the Declaration and the VGM

The completed declaration must reach the carrier or vessel operator before the published dangerous goods cutoff, which typically falls several days before the vessel arrives at the loading port. Carriers accept submissions through Electronic Data Interchange or secure email, and most major lines have online portals for dangerous goods bookings. Terminal operators need time to review hazardous cargo profiles, plan stowage away from incompatible substances, and prepare for gate inspections.

For containerized dangerous goods, a Verified Gross Mass is a separate but parallel requirement. SOLAS Regulation VI/2 requires the shipper to provide a VGM for every packed container before it can be loaded. The VGM must reach both the master (or their representative) and the terminal representative in time to be used in the stowage plan. A container without a verified weight will not be loaded, even if the declaration is otherwise perfect. Even with a verified weight on file, the master retains discretion to refuse any container.⁶

The submission process concludes when the carrier issues a formal acknowledgment of the dangerous goods data. Without that confirmation, you have no proof the declaration was received, which becomes a problem if a dispute arises later. Miss the cutoff and the container generally sits at the terminal until the next available vessel, with storage charges accruing daily.

Keeping the Records

IMDG Code Section 5.4.6.1 requires both the consignor and the carrier to retain a copy of the dangerous goods transport document for a minimum of three months after delivery. Electronic retention is permitted as long as the records can be reproduced in printed form.⁷

U.S. federal law imposes longer retention. Each person who provides or receives a hazardous materials shipping paper must retain a copy or electronic image accessible at their principal place of business for 375 days after acceptance by the initial carrier. For hazardous waste, the period extends to three years. The longer domestic period controls for shipments touching U.S. ports.⁸

What a Wrong Declaration Costs

Under 49 U.S.C. 5123, any person who knowingly violates the hazardous materials regulations faces a civil penalty of up to $75,000 per violation at the base statutory level. If the violation results in death, serious illness, severe injury, or substantial property destruction, the statutory maximum rises to $175,000.⁹ A separate violation accrues for each day a continuing violation persists.

After inflation adjustment, the effective 2026 maximums are $102,348 per day per violation for standard violations and $238,809 per day per violation where death, serious injury, or substantial property damage results.⁸ Training-related violations carry a minimum penalty of $450. PHMSA weighs the nature and gravity of the violation, the company’s history, ability to pay, and any corrective actions when setting the actual amount.

The financial exposure extends past the fine. A carrier that discovers a misdeclared container mid-voyage may divert the vessel or offload the cargo at the next port and bill every cost back to the shipper. Criminal prosecution is also available for serious cases. The paperwork is worth doing carefully.

1
International Maritime Organization. Multimodal Dangerous Goods Form
2
International Maritime Organization. The International Maritime Dangerous Goods (IMDG) Code
3
eCFR. 49 CFR 172.604 – Emergency Response Telephone Number
4
Pipeline and Hazardous Materials Safety Administration. Lithium Battery Guide for Shippers
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eCFR. 49 CFR 171.22 – Authorization and Conditions for the Use of International Standards and Regulations
6
International Maritime Organization. Verification of the Gross Mass of a Packed Container
7
IMO Rules. Chapter 5.4 – Documentation
8
eCFR. Appendix A to Subpart D of Part 107 – List of Frequently Cited Violations
9
Office of the Law Revision Counsel. 49 USC 5123 – Civil Penalty