The cargo was fine. The packing was fine. What stopped the container was a declaration without a signature, and a packing certificate that named a different packing date than the terminal's gate-in record. These things happen every week at every port, and they cost shippers more than the freight.
Carriers do not reject dangerous goods bookings out of caution alone. They reject them because a document is incomplete, contradicts another document, or was signed by someone who cannot show that they were trained to sign it. What follows is the checklist an experienced documentation desk works through before a cut-off, roughly in the order things tend to go wrong.
The core document set
Most ocean carriers accept a single consolidated document — the Multimodal Dangerous Goods Form, often still called the DG declaration or DGD — but that form is only the front page of a small packet. A missing companion paper stops a booking as effectively as a wrong UN number.
- Dangerous goods declaration — the full shipment description, signed and dated by a trained person, matching the booking exactly.
- Container or vehicle packing certificate — often combined into the declaration itself, but it must be the packer's attestation, not the forwarder's.
- Safety data sheet or equivalent product information — not always mandatory for the carrier, but the first thing they ask for when a description looks thin.
- Transport document — the bill of lading or sea waybill has to carry the same DG statement, including the UN number and proper shipping name.
- Emergency contact — a monitored 24-hour number, with the contract reference matching the service actually used.
- Approvals, exemptions or permits — anything that takes the shipment outside the standard rules for its class.
Declaration details that get checked line by line
A carrier's DG desk reads a declaration against the booking confirmation and then against itself. Internal consistency is what matters most: if the packing certificate says eight pallets and the declaration says ten packages, the booking stops there.
Identification of the goods
The UN number, proper shipping name, class and subsidiary hazard, and packing group have to line up with the current edition of the IMDG Code and with each other. Trade names alone are not enough; the proper shipping name must appear with any required technical name in brackets. For Class 3 entries, the flash point in degrees Celsius closed cup is expected on the declaration. For substances that are also marine pollutants, say so explicitly — the "marine pollutant" or environmentally hazardous designation is not something a carrier will guess on your behalf.
Quantities, packaging and weights
Number and kind of packages, net and gross quantity of each dangerous good, and the type of packaging — including any approved packaging instruction reference. Where a shipment contains several UN numbers, list them separately rather than grouping them under one total. Consolidated cargo is where most discrepancies hide, because two shippers' paperwork has to agree before the forwarder can issue anything.
Labels, marks and what the photographs show
Carriers increasingly ask for photographs of the packed unit before the container goes to the terminal, and a photo reveals a lot: a missing class label on a drum, an overpack without the word "OVERPACK" and its own marks, orientation arrows pointing at the floor. Beyond the hazard labels on each package, the freight unit itself needs the placards or orange plates appropriate to its contents, and the marine pollutant mark where it applies. A container that last carried dangerous goods and has not been cleaned carries the "empty, uncleaned" marking — and that marking has to survive until the unit is genuinely clean.
The packing certificate is not a formality
This is the document that most often comes back unsigned, and it is the one that shifts responsibility. By signing it, the packer confirms the unit was inspected before loading, that the goods were properly segregated and secured, that the packages were undamaged, and that the unit and its fittings were in suitable condition. Signatures from someone in an office who has never seen the container are common and are a weak point: if a carrier queries the packing, they will ask who signed and what that person's role was on site. Train the people who sign, keep a record of that training, and make sure the name on the certificate belongs to someone who can describe the loading.
Common errors that trigger rejections
Most rejections fall into a short list of familiar mistakes. Reviewing for these takes ten minutes and saves days.
- Mismatched descriptions. The bill of lading says "chemicals, non hazardous"; the declaration says Class 8. One of them is wrong, and the carrier will assume the worst.
- Missing or generic emergency number. A switchboard number that closes at 5pm is not a 24-hour contact.
- Wrong total quantity. Net quantity per UN number missing, or gross weight that cannot be reconciled with the verified weight.
- Unsigned declaration or certificate, or signed by someone whose name was typed in by a colleague.
- Expired or missing approvals for non-standard packaging, portable tanks or exemptions.
- Labels inconsistent with the declared class — usually a leftover label from a previous product run.
- Language and legibility. Handwritten amendments, faxed copies, or a scanned document too poor to read at the gate.
A two-pass check before cut-off
Run the paperwork twice. On the first pass, check each document against the booking: names, addresses, UN numbers, quantities, ports, vessel and voyage. On the second pass, check the documents against each other, because that is where contradictions surface. Then ask one person who did not prepare the file to read it. Fresh eyes catch the missing page that familiarity skips.
Keep a copy of everything you submitted, including the version the carrier accepted, and note who signed what and when. When a query arrives after departure, that file is what resolves it.
A final practical note: rules for dangerous goods vary by class, packaging type and carrier acceptance policy, and the IMDG Code plus the individual carrier's conditions govern each shipment. For anything outside routine traffic — new products, mixed consignments, portable tanks — take advice from a qualified dangerous goods professional before you book.
Photo: socialneuron / Pixabay
