Placarding Hazmat Vessel Shipments

Posted on 12/16/2014 by Robert Clarke

Transporting materials by vessel is a dangerous business. Incidents are not uncommon and can threaten the cargo and crew. Rogue waves and human error can be a hazard in themselves; adding dangerous goods to the mix can be a recipe for disaster.

Identifying dangerous goods and communicating their hazards to port and vessel personnel is vital to worker safety and the on-time delivery of the cargo. In every even-numbered year, the International Maritime Organization (IMO) publishes a new edition of its International Maritime Dangerous Goods Code (IMDG Code). This manual lays out the international standards US hazmat shippers must follow in addition to DOT regulations to send shipments by vessel.

Find the hazmat labels and placards you need to ship by ground, air, and sea at

Communicating Hazards for Vessel Transport

Placards are used to indicate that a Cargo Transport Unit (CTU) contains dangerous goods and what kind. Dangerous goods vessel shippers must placard CTUs in accordance with the specifications at IMDG Code Placards must:
  • Be a minimum of 250 mm on each side, and
  • Match the same specifications for symbol and color as required for labels in IMDG, and
  • Display the hazard class or division in numbers at least 25 mm high.
Text such as "Flammable Liquid," "Corrosive," etc., is not required on placards. (The exception are placards for radioactive shipments, which must show the appropriate UN Number or the word "Radioactive.") Text is not prohibited under the IMDG Code, however, so DOT specification placards, which do require text, are permitted for use on vessels.

In addition, to ensure continued communication in the event of an incident at sea, placards must be durable enough to survive three months' immersion in the sea. [IMDG]

When Are Placards Required?

Unless specifically excluded, CTUs containing any amount of dangerous goods must be placarded for the dangerous goods they contain. In most cases, the placards must be displayed on all four sides of the CTU. [IMDG] The IMDG Code does not specify exactly where on each side the placards must be placed, but it does require that placards be clearly visible and stand out from their background, or that they have a solid or dotted outside border. [IMDG]

Placards must be displayed once the dangerous goods are offered for transport and removed once the dangerous goods have been unloaded. Placards for both the primary and the subsidiary hazards of all materials in the CTU must be displayed on the outside of the CTU. [IMDG] (Special rules for placarding CTUs containing radioactive materials can be found at IMDG

When Are Placards Not Required?

Placards are not required on CTUs if the markings and labels are clearly visible from the outside or if the CTUs only contain limited quantity or excepted quantity packages. [IMDG and] Placards are also not required on CTUs that contain any Division 1.4, Compatibility Group S explosive materials. If CTUs contain substances and articles in more than one division of Class 1, the CTUs only need to display the placards representing the highest risk. [IMDG] A DOT Extra

The US Hazardous Material Regulations require additional placarding and other communications for toxic inhalation hazard materials in Divisions 2.3 or 6.1, even if the shipment is otherwise prepared under the IMDG Code. [49 CFR 171.23]

Placarding requirements are an essential part of shipping dangerous goods by vessel. The latest edition of the IMDG Code, the 2014 edition, includes many changes to the vessel shipping rules. As with each new IMDG Code edition, compliance is voluntary in the year following publication (2015) and mandatory in the next even-numbered year (2016).

Prepare for Compliance with the 2014 IMDG Code

To help vessel shippers ensure compliance with the latest IMDG Code regulations, Lion Technology will present the Hazmat Vessel Shipper Certification (IMDG) Webinar on January 22. The webinar will cover the latest rules and is designed to meet the training requirement for hazmat vessel shipping personnel at IMDG 1.3 and 49 CFR 172.704(c). Attendees get an easy-to-download Compliance Reference, a copy of the presentation, and 365 days of complete follow-up support for answers to regulatory questions, online rule updates, discount on select Lion products, and more.

Tags: hazmat, IMDG, shipping

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