IMDG Regulations Simplified: Quick Tips for Safe and Compliant Shipping

Shipping hazardous materials by sea is a high-stakes task. One mistake can lead to serious accidents, environmental harm, or costly penalties. Yet, understanding the International Maritime Dangerous Goods (IMDG) Code, the global rulebook for safe transport, can feel overwhelming. That’s why we’ve simplified the essentials into practical tips that you can start to apply immediately to keep shipments moving safely and efficiently.

Dangerous Goods vs. Hazardous Materials

Hazardous materials or dangerous goods are articles or substances capable of posing a risk to health, safety, property, or the environment during transportation in commerce. While the term “dangerous goods” is commonly used worldwide, in the United States “hazardous materials” is the preferred term. We tend to use the terms interchangeably.  

What Are IMDG Regulations?

The IMDG Code sets international rules for shipping dangerous goods by vessel. Developed by the International Maritime Organization (IMO), it's updated every two years to keep pace with UN model regulations.

These regulations promote safety by:

• Classifying hazardous materials by type and risk level
• Outlining proper packaging, labeling, and documentation
• Establishing stowage and segregation practices
• Requiring emergency response procedures

The goal is simple: protect lives, property, and the environment while keeping supply chains moving. For businesses, adhering to IMDG regulations isn’t just about safety; it’s about avoiding costly delays, fines, and reputational damage. Non-compliance can lead to rejected shipments, supply chain disruptions, and increased liability in case of an incident, impacting both operations and customer relationships. Understanding the core principles is the first step toward confident, compliant shipping.

Quick Tips for IMDG Compliance

Simplifying IMDG compliance starts with these key steps:

1. Know Your Classification

Proper classification is the first and most critical step in IMDG compliance. Every hazardous material falls under one of nine classes, ranging from explosives (Class 1) to miscellaneous dangerous goods (Class 9). Each class reflects the specific risks associated with the substance.

To classify a shipment correctly:

• Identify the UN number, a unique four-digit code assigned to each hazardous material.
• Use the Proper Shipping Name (PSN) listed in the IMDG Code to describe the material accurately. Trade names aren't accepted.
• If applicable, determine the Packing Group (PG)—I, II, or III—based on the degree of hazard, with I being the highest.

2. Label and Mark Properly

Proper labeling and marking are essential for safe handling and compliance. The IMDG Code specifies that most packages must display labels that clearly identify the hazards they present. These labels alert handlers, transporters, and emergency responders to potential risks.

Key labeling requirements include:

• Hazard Class Labels: Displayed on one surface for non-bulk containers or on two sides of an IBC, corresponding to the material’s hazard classification.
• Marine Pollutant Mark: Required if the substance is harmful to the aquatic environment. This mark helps prevent accidental environmental contamination.
• Elevated Temperature Mark: Needed for substances shipped at or above 100°C (liquids) or 240°C (solids).

3. Package According to Standards

The IMDG Code (Part 4) provides detailed packing instructions for each type of hazardous material. These instructions specify the type of packaging allowed, from fiberboard boxes to portable tanks, based on the substance’s classification and packing group.

Key packaging requirements include:

• Certified Containers: Only use UN-certified packaging tested for durability and leakage prevention. Look for the UN certification mark on all containers. As well as bulk containers approved by competent authorities.  
• Intermediate Bulk Containers (IBCs): Suitable for bulk liquids and solids, IBCs must be tested for stacking strength and impact resistance.
• Secured Stowage: Packages must be secured to prevent movement during transit. Improperly secured cargo can shift, damaging containers and increasing the risk of spills.

4. Follow Segregation Rules

IMDG segregation rules prevent dangerous chemical reactions between incompatible substances during transport. The code provides a segregation table and flowchart to guide proper segregation and stowage.

Segregation levels range from “away from” to “separated by a complete compartment.” For example:

• Class 5.1 (Oxidizers) like ammonium nitrate cannot be stored near Class 4.1 (Flammable Solids), as oxidizers can intensify fires.
• Class 6.1 (Toxic Substances) must be separated from Class 8 (Corrosives) to prevent chemical reactions that could release toxic gases.

5. Document Everything Accurately

Accurate documentation supports smooth shipping and avoids costly delays. IMDG documentation serves as a legal declaration of the shipment’s contents and handling requirements.

Essential documents include:

• Dangerous Goods Declaration (DGD): This form lists the UN number, Proper Shipping Name, hazard class, packing group (if applicable), and quantity.
• Multimodal Dangerous Goods Form: Required when shipments move across different transport modes like sea, road, and rail.
• Container/Vehicle Packing Certificate: Confirms that cargo was packed and secured in compliance with IMDG standards.
• Emergency Contact Information: Must be included on shipping papers to facilitate rapid response in case of an incident.

6. Train Your Team

IMDG regulations mandate training for all employees involved in the transport of hazardous materials. This includes shippers, packers, freight forwarders, and vessel operators.

Training must cover:

• General Awareness: Understanding the IMDG Code and its application.
• Function-Specific Training: Hands-on instruction tailored to each employee’s role.
• Safety Training: Emergency response protocols for spills, fires, or exposures.
• Refresher Courses: Required every three years, but would recommend two years to stay current with IMDG amendments.

7. Prepare for Emergencies

Even with careful planning, incidents can occur. IMDG regulations require that emergency response plans accompany every hazardous shipment. These plans should be accessible to ship crews, port staff, and emergency responders.

Key components of an emergency plan include:

• Emergency Response Guide (ERG): Outlines steps for firefighting, spill containment, and medical treatment.
• Medical First Aid Guide (MFAG): Provides specific guidance for treating chemical exposure or injuries.
• Emergency Contact Information: 24/7 availability of hazmat specialists, like CHEMTREC, to provide critical information during an incident.

By following these preferred practices, you can reduce the risk of delays, fines, and accidents. However, even the most thorough processes rely on well-trained staff who can apply these standards consistently.

How CHEMTREC’s New Shipping Dangerous Goods by Vessel Course Can Help

Navigating IMDG regulations doesn’t have to be complicated. CHEMTREC’s new Shipping Dangerous Goods by Vessel course provides clear, practical training for hazardous materials professionals, involved in shipments by vessel.

The course covers:

• Regulatory overview on transporting dangerous goods by vessel
• Hazard classification and documentation
• Navigating the dangerous goods list
• Proper labeling, marking, and packaging
• Stowage, segregation, and compatibility practices
• Emergency response and security readiness

Designed for flexibility, the course is available online, allowing learners to complete it at their own pace. Certification upon completion demonstrates your team’s commitment to safety and compliance, whether you’re shipping hazardous goods occasionally or managing daily operations.

Don’t let complex regulations put your business at risk. Empower your team with the skills they need to ship safely and confidently. Explore CHEMTREC's new Shipping Dangerous Goods by Vessel course today.