Dangerous goods include a wide variety of materials and substances that pose risks to people, property and the environment. These risks arise from their unique chemical or physical properties, making them potentially dangerous under certain conditions. Whether flammable, toxic, reactive, corrosive or radioactive, each category of hazardous goods requires special handling to avoid accidents or environmental damage.
These goods are categorised based on their specific risks and the precautions required when handling them. The IMDG (International Maritime Dangerous Goods) Code classifies new main classes, each containing different substances with unique hazard profiles:
Class 1: Explosives
Explosives can decompose quickly, causing intense pressure and heat. There are six subcategories, ranging from substances with a mass explosion hazard, such as certain chemical powders, to substances with minimal transport risk, such as fireworks. Due to the risk of explosion, these substances must be handled and stowed with extreme caution.
Class 2: Gases
Gases are usually transported under pressure in cylinders or other special containers, so leaks are particularly dangerous. They can be further divided into flammable, non-flammable (compressed) and toxic gases.
Class 3: Flammable liquids
Flammable liquids ignite easily and often produce vapours that can cause explosive reactions. Examples include gasoline, ethanol, acetone, and certain types of paint. Because of their volatility, they are subject to strict temperature controls and must be kept away from potential ignition sources.
Class 4: Flammable solids, substances liable to spontaneous combustion, and substances that emit flammable gases when wet
These substances often need to be transported in dry, well-ventilated conditions and separated from liquids to avoid accidental reactions. This class is divided into three categories:
Class 5: Oxidising substances and organic peroxides
Substances that give off oxygen are a major hazard near combustible materials because they can increase combustion. They also require cooling systems and controlled environments.
Class 6: Toxic and infectious substances
Class 6 includes substances that are harmful to health if directly exposed to or inhaled. They are usually packaged in a specially sealed manner. Examples include:
Class 7: Radioactive material
The ionising radiation from radioactive goods poses health risks for people and contamination risks for the environment. These include, for example, medical isotopes, uranium and plutonium. These materials are subject to the strictest regulations, including limits on the permissible amount of radiation during transport and requirements for shielding measures to protect people from the radiation.
Class 8: Corrosives
Corrosives can destroy organic tissue and corrode metals, causing severe burns or structural damage. They are usually stored in durable containers and kept away from substances with which they could chemically react. They include:
Class 9: Miscellaneous dangerous goods
Class 9 is a catch-all category for dangerous goods that do not clearly fit into other classes but still pose a risk. This includes materials such as lithium batteries (with the risk of overheating or explosion), environmentally hazardous substances, and other unique items such as airbags and dry ice. Handling requirements for materials in this class vary depending on the specific risks involved.
Each class of dangerous goods brings its own risks and handling requirements that must be strictly adhered to. Knowledge of the different types and their specific properties and requirements is the basis for maintaining safe and compliant logistics operations.
There are several external challenges that go beyond the inherent risks of the cargo itself and affect the safe and efficient transport of dangerous goods in maritime logistics. Here is a look at some of these "external" challenges:
Regulations and compliance
The transport of dangerous goods is subject to various international and regional regulations and recommendations, including the United Nations Recommendations on the Transport of Dangerous Goods (UN Model Regulations), which a large number of countries follow. Failure to comply with the rules applicable to the specific transport route can lead to penalties, cargo rejection and even suspension of transport rights.
Regulations must also be complied with in terms of environmental protection. Some ports may have rules prohibiting certain classes of dangerous goods for ecological reasons, requiring diversion or additional planning.
Documentation errors
Transporting dangerous goods requires precise and accurate documentation. Errors in labelling or documentation can lead to improper stowage or handling.
A study conducted by the U.S. National Cargo Bureau (NCB) with support from some of the world's largest shipping companies found that 6.5% of containers carried misdeclared dangerous goods, such as charcoal, flammable liquids and used lithium-ion batteries (1).
Containment failures and packaging risks
If containers are improperly sealed or damaged, this can lead to leaks, spills, or mixing incompatible chemicals. The solutions used directly to pack and secure the cargo in the containers can also cause breakage, spills or moisture exposure, and their consequences if they are not tailored to the specific needs of the goods and cannot withstand the stresses of sea transport.
The NCB study mentioned above found that more than half (55%) of the inspected containers did not comply with national regulations for dangerous goods transport. In addition, in 43% of the containers, the hazardous goods were found to be poorly secured.
Incidents from external conditions
Storms, high seas and rough handling can cause containers to shift, tip over or become physically damaged. Extreme temperatures occurring during increasingly frequent heat waves pose a risk to materials that can become unstable at excessive temperatures.
Ports in areas prone to tropical storms or hurricanes face the additional risk of storm surges, damaging port infrastructure and flood storage areas, and exposing dangerous goods to moisture or physical impact.
Natural disasters such as earthquakes, tsunamis, and volcanic eruptions also endanger delicate cargo by possibly damaging the containers themselves or the storage facilities and handling equipment.
Geopolitical and security risks
Sudden political changes, trade restrictions or sanctions against certain hazardous substances can lead to significant disruptions to transport routes.
Some shipping routes run through high-risk zones for piracy. Dangerous goods, especially those with potential dual use (such as explosives or toxic chemicals), can become targets for theft.
The increasing use of digital systems to monitor and manage shipments also makes the transport of dangerous goods vulnerable to disruption of the flow of information, which can lead to miscommunication, for example, regarding the location and condition of the cargo.
Port congestion, delays, and human error
Operational bottlenecks can cause delayed storage and longer waiting times for time and temperature-sensitive materials. If the area designated for hazardous goods is not large enough, this often leads to unsafe storage practices. Another bottleneck is not (enough) adequately trained staff, which can lead to incompatible materials being accidentally placed close to each other or errors being made during loading or unloading.
The external challenges require robust contingency plans, multi-layered risk management practices and adaptable supply chain solutions. Effective preparation and response are essential to maintain safe, compliant, and efficient freight handling at every stage of dangerous goods transport.
Dangerous goods transport is subject to a complex network of regulations designed to ensure safety, prevent environmental damage and protect human life. Although variations depend on the country and mode of transport, they all have one thing in common: they aim to set clear standards for the classification, packaging, labelling and handling of dangerous substances. In this chapter, we present five of these regulations:
International regulations
UN Recommendations on the Transport of Dangerous Goods (The Orange Book)
The UN recommendations form the basis for many other transport regulations. They provide a comprehensive framework across all modes of transport and aim to ensure global consistency and safety in transporting dangerous goods.
IMDG Code (International Maritime Dangerous Goods Code)
It contains guidelines for the classification, packaging, labelling and documentation of dangerous goods transported by sea. It also contains emergency measures suitable for sea transport. It is legally binding under the SOLAS (Safety of Life at Sea) Convention.
Regional Regulations
49 CFR (Code of Federal Regulations, Title 49) – U.S. Department of Transportation
This regulation regulates the transportation of dangerous goods by all modes of transport (road, rail, air, and sea) within the United States. 49 CFR enforces safety standards consistent with U.S. obligations under international conventions such as the IMDG Code and EU regulations.
ADN (Accord européen relatif au transport international des marchandises Dangereuses par voies Navigables)
ADN regulates the transport of dangerous goods by inland waterways in European countries. Like other regulations, it is regularly updated to reflect new technological advances and emerging safety concerns.
Transportation of Dangerous Goods Act (Canada)
This regulation sets safety standards for the handling and transporting of dangerous goods within Canada and is enforced by the Canadian Transportation Agency.
Labels and placards are essential tools for identifying and warning about cargo-related hazards. They communicate important safety information to anyone who handles or interacts with the shipment.
They also play a crucial role in emergency response. The information they contain helps emergency responders identify the specific hazards and take appropriate action. For example, they indicate whether firefighting techniques or protective clothing are required when dealing with a spill or accident involving dangerous goods.
Labels
Labels are usually 100 mm x 100 mm square or diamond-shaped symbols placed on individual packages near the hazard class number. Each hazard class is represented by a specific colour, often with a distinctive symbol or pictogram to highlight the nature of the hazard. International regulations include prescribed criteria for design, placement, legibility and durability.
Placards
Placards are larger signs (250 mm x 250 mm or larger) that warn more clearly of the presence of dangerous goods and are usually placed on vehicles, transport containers or transport units so that they are visible from a distance. They show a symbol, a hazard class number and sometimes additional numbers or information. A duplicate plaque may be required if different types of dangerous goods are being transported.
Safety Data Sheets (SDS)
More detailed documents are safety data sheets, typically including 16 sections, such as physical and chemical properties and first aid measures.
The SDS must be generally available in the language of the country to which the goods are transported and should be accessible to all parties involved in the handling or transporting of the goods, including drivers, warehouse workers and emergency services.
In container terminals, the stowage of containers containing hazardous goods must be carefully planned. It is crucial to ensure the safety of personnel and the protection of equipment, as well as to keep the risk to other cargo as low as possible.
Designated hazardous goods zones
In most ports, designated areas are specially designed for this sensitive cargo. They are usually located away from busy areas and important buildings for administration and other offices. Isolated areas limit the risks of an incident, such as a chemical leak.
Segregation requirements
Different types of hazardous goods must also be separated within the designated zone. International regulations regulate which kinds of hazardous substances must be stored separately due to their possible reactions.
Accessibility for emergency response
An essential factor for the success of emergency measures is that the containers affected are easily accessible. The paths and open spaces around the containers must be designed so emergency vehicles can reach them quickly. In addition, sufficient safety equipment such as fire extinguishers, containment kits and special protective equipment must be available as close as possible.
Proximity to water sources for fire suppression
Proximity to water sources is also essential. Fire is a significant risk when handling hazardous materials, so there should be nearby water sources as well as special fire extinguishing agents such as foam-based extinguishing agents. The latter is particularly important if the cargo contains petroleum products.
Ventilated and temperature-controlled areas
Certain hazardous goods must be stowed in well-ventilated or temperature-controlled areas, especially those emitting toxic gases or prone to heat-related reactions. Air circulation systems in ventilated storage areas can prevent the formation of hazardous vapours. For cargo transported refrigerated in reefers, reefer plugs must be available in sufficient numbers.
Height restrictions and stacking policies
Containers carrying hazardous materials are usually subject to stricter height and stacking restrictions than other dry containers. This is to ensure that they are accessible and stable. In addition to making monitoring more straightforward, this is also intended to minimise the risk of tipping or slipping during handling.
Automated monitoring and alarm systems
At modern terminals, the areas designated for hazardous materials are equipped with integrated sensors and alarm systems. These technologies monitor conditions such as temperature, gas emissions and potential leaks. If the values of each parameter deviate, the system can trigger alarms, notify personnel and initiate a response protocol.
Temporary stowage areas
In some cases, there are temporary holding areas intended for containers to stay only for a short period. They are often located near loading or unloading points to minimise the time spent at the terminal.
Particular protocols for high-risk containers
Highly hazardous materials, such as toxic gases or radioactive materials, are subject to even more specialised protocols, security measures, and stricter isolation. They require their own training, and often, additional precautions are taken to prevent unauthorised access.
Incidents involving dangerous goods occur frequently. Many of us probably remember one that took place just three months ago.
On August 9, 2024, at 1:40 p.m. local time, a container exploded on the YM Mobility. Fortunately, there were no injuries, only property damage, and due to the immediate fire control measures, the fire was soon brought under control and extinguished.
Yang Ming, the vessel's owner, released the following statement: "Preliminary findings suggest that an explosion occurred in a container loaded with dangerous goods on board. According to the shipper's declaration, the container was a reefer used as a substitute for a dry container, without requiring a power connection."
As a result of this incident, the China Maritime Safety Administration (MSA) has imposed stricter rules on dangerous goods passing through the affected Ningbo port (2).
It underlines the need for all companies involved in transportation to implement safety protocols, including measures during high-temperature seasons and thorough training and safety education for employees and crew members. (3)
With suitable preventive measures, many incidents can be avoided. Both operational and technological strategies are used to improve safety:
Preventing dangerous goods incidents during transport requires a combination of strict regulatory compliance, well-trained personnel and increasingly sophisticated automation solutions. As safety protocols evolve and monitoring and high-risk tasks become automated, the future of dangerous goods transport will be safer, more efficient and more resilient.
Why can't flammable goods and oxidising agents be stored next to each other?
If these two types of cargo are stored close to each other, the risk of a severe fire or explosion increases dramatically. This combination is perilous for the following reasons:
Accelerated combustion
Oxidisers release oxygen or other reactive substances that can intensify combustion. If flammable material catches fire nearby, the oxidiser can provide additional oxygen to the flame, causing the fire to spread faster and burn with greater intensity. This can make the fire very difficult to control and require special firefighting equipment and techniques.
Increased risk of explosion
Certain oxidisers and flammable materials can react violently with each other, generating heat or gas or even causing an explosive reaction. A spark or simple friction can often cause an explosion with devastating consequences.
Chain reaction potential
The fires and explosions described above can also cause a domino effect. Heat or explosive force can affect other containers nearby, causing dangerous cargo such as toxic or corrosive substances to leak, further escalating the incident.
Environmental hazards
The fires also release a lot of toxic smoke and pollutants into the air. In a port or terminal near water, these pollutants could also contaminate soil and water, causing environmental damage that could impact local ecosystems.
We have learned that dangerous goods transport is a complex undertaking that requires precision, expertise and vigilance at every step. International regulations govern the processes, from correctly packing and carefully stowing goods in containers to careful transport and appropriate storage.
Global cooperation and innovative safety measures, from advanced monitoring technologies to evolving risk management techniques, are helping to make the transport of dangerous goods ever safer. Learn more about safety in ports here.
Delve deeper into one of our core topics: Port Automation
Sources:
(1) https://www.wtwco.com/en-us/insights/2024/09/hazardous-materials-and-ports-mis-declared-cargoes-continue-to-highlight-industry-safety-issues
(2) https://theloadstar.com/china-tightens-rules-on-hazardous-cargo-at-ningbo/
(3) https://safety4sea.com/cargo-integrity-group-urges-enhanced-safety-following-ningbo-zhoushan-port-explosion/