If you are new to shipping and you have just discovered that your goods might be classified as dangerous, do not panic. This article explains everything you need to know, in plain English, so you can move forward with confidence and stay on the right side of the law.
Dangerous goods shipping is one of the most tightly regulated areas of international trade. Getting it wrong can mean rejected shipments, heavy fines, or in serious cases, criminal liability. Getting it right is straightforward once you understand the framework.
Dangerous goods (also called hazardous materials or “hazmat”) are substances and articles that pose a risk to health, safety, property, or the environment when transported. They are defined and classified by international regulations, and the classification determines everything from how they are packaged to what paperwork you need.
The term covers a much wider range of products than most people expect. Perfume, paint, aerosols, cleaning products, lithium batteries, and medical samples can all qualify as dangerous goods. You do not need to be shipping explosives or radioactive material to fall under these rules.
The key point is this: the classification is based on the nature of the substance, not on how dangerous it feels. As the shipper, it is your responsibility to know whether your goods are classified as dangerous before you book a shipment.
Dangerous goods are divided into nine classes by the United Nations. Each class covers a specific type of hazard. Some classes have sub-divisions.
| Class | Name | Examples |
|---|---|---|
| 1 | Explosives | Fireworks, ammunition, flares |
| 2 | Gases | LPG, aerosols, compressed oxygen, fire extinguishers |
| 3 | Flammable Liquids | Petrol, paint, adhesives, alcohol, perfume |
| 4 | Flammable Solids / Substances Liable to Spontaneous Combustion / Substances that Emit Flammable Gas in Contact with Water | Matches, metal powders, calcium carbide |
| 5 | Oxidising Substances and Organic Peroxides | Bleach, hydrogen peroxide, fertilisers |
| 6 | Toxic and Infectious Substances | Pesticides, medical/biological samples, diagnostic specimens |
| 7 | Radioactive Material | Medical isotopes, industrial radiography equipment |
| 8 | Corrosive Substances | Battery acid, drain cleaner, mercury |
| 9 | Miscellaneous Dangerous Substances and Articles | Lithium batteries, dry ice, magnetised material, elevated temperature substances |
Class 9 catches everything that does not fit neatly into Classes 1–8 but still poses a transport risk. Class 9 includes lithium batteries, one of the most common compliance issues for UK shippers today.
The International Maritime Dangerous Goods (IMDG) Code governs dangerous goods shipped by sea. It is published by the International Maritime Organization (IMO) and updated every two years.
In the UK, the Maritime and Coastguard Agency (MCA) is the competent authority for sea transport of dangerous goods. The IMDG Code sets out how goods must be classified, packed, labelled, marked, and documented before they can be loaded onto a vessel.
The Code is mandatory for international voyages. It applies whether you are shipping a single carton or a full container load. Carriers and ports check compliance at every stage, and non-compliant shipments will be refused.
Key requirements under IMDG include correct packaging, hazard labels, placards on containers, and a Dangerous Goods Note (DGN) accompanying the shipment.
Air freight is the most tightly controlled mode for dangerous goods. The IATA Dangerous Goods Regulations (DGR) manual is the global standard for shipping dangerous goods by air. Airlines will not accept a shipment that does not comply.
In the UK, the Civil Aviation Authority (CAA) is the competent authority. The CAA oversees training, approvals, and enforcement for dangerous goods shipped by air.
Many substances that can travel by sea are completely forbidden by air, or can only travel in very limited quantities. Flammable liquids, compressed gases, and lithium batteries all face strict restrictions in the air freight environment.
Before booking any air shipment, check the IATA DGR to confirm your goods are permitted. If they are, confirm the quantity limits, packaging requirements, and labelling rules that apply.
Road transport of dangerous goods within Great Britain and across Europe is governed by the ADR Agreement: the European Agreement Concerning the International Carriage of Dangerous Goods by Road.
The Driver and Vehicle Standards Agency (DVSA) is the UK competent authority for road transport of dangerous goods. In practice, ADR rules apply to most commercial road movements of hazardous substances.
ADR requires that drivers hold an ADR certificate (also called a Kemler licence) and that vehicles are properly equipped and placarded. The goods must also be correctly packaged and documented. Not every shipment triggers full ADR requirements: there are thresholds below which reduced obligations apply.
For rail, the equivalent regulations are known as RID (Regulations Concerning the International Carriage of Dangerous Goods by Rail).
The first step is to check the Safety Data Sheet (SDS) for your product. Every chemical and hazardous substance should have one. The SDS will tell you whether the substance is classified as dangerous for transport and, if so, which class applies.
For finished consumer goods, such as aerosols, perfumes, or battery-powered products, check the product label and any technical documentation from the manufacturer.
You can also search the UN Dangerous Goods List. Every classified dangerous good is assigned a UN Number, which we will cover in the next section.
If you are still unsure, consult a qualified Dangerous Goods Safety Adviser (DGSA). This is especially important if you are shipping regularly or in volume.
Three pieces of information sit at the core of any dangerous goods shipment.
UN Number: a four-digit number assigned by the United Nations to identify a specific dangerous substance or group of substances. For example, UN 1950 = Aerosols. UN 1263 = Paint. UN 3480 = Lithium ion batteries. The UN Number must appear on the package and on the transport documents.
Proper Shipping Name (PSN): the official name used in transport documentation. You cannot use a trade name or a common name. You must use the exact name from the UN Dangerous Goods List. For example, “Aerosols, flammable” rather than “hairspray” or “deodorant.”
Packing Group (PG): a classification of the degree of danger within a class. Not all classes use packing groups. Where they apply, the groups are:
The packing group affects what type of packaging you must use and what quantities are permitted in certain modes of transport.
Packaging for dangerous goods is not optional and it is not generic. The packaging you use must be specifically tested and approved for the substance you are shipping.
UN-certified packaging has been tested to withstand drop, stacking, and leakage. Each approved package carries a UN mark showing the type, performance level, and testing details. You cannot substitute unapproved packaging, even if it looks strong enough.
The rules vary by class, packing group, and mode of transport. Some substances require inner and outer packaging combinations. Others must be packed with absorbent material or cushioning.
Always get packaging from a supplier who can confirm the UN certification is right for your specific substance, quantity, and mode of transport.
Every dangerous goods shipment must travel with the correct paperwork. Missing or incorrect documentation is one of the most common causes of shipment delays and refusals.
Shipper’s Declaration for Dangerous Goods: required for air freight. This is a signed declaration completed by the shipper confirming the goods are correctly classified, packed, and labelled. It must accompany the airway bill.
Dangerous Goods Note (DGN): required for sea freight. The DGN is the primary transport document for dangerous goods moving by sea. It includes the UN Number, Proper Shipping Name, class, packing group, quantity, and emergency contact details.
Emergency Contact: all dangerous goods shipments must include an emergency telephone number where someone with knowledge of the goods can be reached at any time.
Multimodal Transport: if your goods move by more than one mode (for example, road to port, then sea), documentation must comply with the rules for each mode.
A good freight forwarder will have trained dangerous goods staff and the necessary approvals to handle your shipment. Before booking, confirm that your forwarder:
Do not assume your forwarder will catch errors in your documentation or classification. As the shipper, you remain responsible for the accuracy of the information you provide. If you declare a substance incorrectly, the legal liability rests with you, not with the forwarder.
Be transparent about what you are shipping from the very first conversation. A reputable forwarder would rather turn down a shipment than accept one that is non-compliant.
The most common mistakes in dangerous goods shipping are:
Non-declaration: shipping dangerous goods without declaring them. This is the most serious offence. It can result in shipment seizure, fines running into thousands of pounds, and in the most serious cases, criminal prosecution.
Incorrect classification: assigning the wrong class, UN Number, or Proper Shipping Name. This leads to wrong packaging and wrong labelling, which creates the same risks as non-declaration.
Wrong packaging: using non-UN-certified packaging or packaging rated for a different packing group. Packaging that fails in transit can cause fires, leaks, and injuries.
Incomplete documentation: missing the shipper’s declaration, incorrect quantities, or wrong emergency contact details. Shipments with incomplete paperwork will be held or returned at the shipper’s cost.
The consequences are serious. Airlines and shipping lines take non-compliance very seriously. A single rejected shipment can damage your relationship with a carrier. Repeat offences can result in permanent bans from using a carrier’s network.
Lithium batteries deserve special attention. They are everywhere in modern consumer goods: phones, laptops, power tools, e-bikes, medical devices. They are also one of the most common sources of non-compliance in international shipping.
Lithium batteries fall under Class 9 (Miscellaneous Dangerous Substances). They are subject to strict restrictions, particularly for air freight, because they can overheat, catch fire, and in some cases explode.
The key distinction is between lithium ion (rechargeable) and lithium metal (non-rechargeable) batteries. Each type has its own UN Number and its own set of rules.
For air freight, IATA imposes strict limits on the state of charge, quantity per package, and how batteries can be shipped, whether alone, contained in equipment, or packed with equipment. Some configurations are only permitted on cargo aircraft, not passenger aircraft.
If you are shipping any product that contains or includes batteries, check the IATA DGR before you book. Do not assume that because the product is a finished consumer good, the batteries inside it are exempt.
Brexit changed the regulatory environment for dangerous goods in some areas, but not as dramatically as many shippers feared. The core international frameworks (IMDG, IATA DGR, ADR) remain in force and the UK continues to apply them.
The main changes affect road transport between Great Britain and the European Union. Cross-border movements by road now require compliance with both UK ADR (as applied in Great Britain) and EU ADR rules. Northern Ireland has its own arrangements under the Windsor Framework.
For sea and air freight, the international regulations apply regardless of Brexit. The IMDG Code and IATA DGR are not EU instruments. They are UN and ICAO frameworks that the UK applies independently.
The practical implication for UK shippers is that extra customs documentation is now required when moving dangerous goods between Great Britain and the EU. Your freight forwarder should be handling this. But it is worth confirming that DG-specific customs codes and consignments are being handled correctly.
Imagine you run a UK health and beauty brand. You want to export aerosol deodorants to a distributor in Germany.
Step 1: Identify the classification. Aerosols containing a flammable propellant are Class 2.1 (Flammable Gas). The UN Number is UN 1950. The Proper Shipping Name is “Aerosols, flammable.”
Step 2: Choose your mode. You decide to ship by road freight to keep costs down. The shipment will travel under ADR rules. You confirm with your freight forwarder that the quantity stays within the ADR thresholds.
Step 3: Check packaging. Your aerosols are already in their retail packaging. But you need to confirm the outer carton is enough for ADR, and that the total quantity per package does not exceed the limits for Class 2.
Step 4: Prepare documentation. Your forwarder prepares the ADR transport document with the correct UN Number, Proper Shipping Name, class, total quantity, and your emergency contact number.
Step 5: Label the packages. The outer cartons must carry the Class 2 hazard label (a flame on a red background) and the UN Number.
Your shipment is now ready to move: legally, safely, and with full compliance.
What is the difference between dangerous goods and hazardous materials?
There is no practical difference. “Dangerous goods” is the term used in international transport regulations (IMDG, IATA DGR, ADR). “Hazardous materials” or “hazmat” is more commonly used in the United States. In the UK, you will mostly see “dangerous goods” in regulatory contexts.
Do I need to declare lithium batteries inside a laptop I am shipping?
Yes. Lithium batteries contained in equipment (such as laptops) must still be declared and shipped in compliance with the relevant regulations for the mode of transport. For air freight, specific IATA conditions apply.
Can I ship dangerous goods with a regular parcel carrier?
Most standard parcel carriers do not accept dangerous goods, or only accept certain classes in limited quantities. Always check with the carrier before booking. Shipping dangerous goods through a carrier that has not agreed to accept them is a serious offence.
What is a Dangerous Goods Safety Adviser (DGSA)?
A DGSA is a qualified professional appointed to advise businesses that transport dangerous goods. In the UK, certain types of dangerous goods operations legally require a DGSA. Even where it is not legally required, having access to a DGSA is strongly recommended.
What happens if my dangerous goods shipment is rejected?
The shipment will be held at the carrier’s facility. You will be responsible for the costs of storage and return. The carrier may also report the non-compliance to the relevant authority. In serious cases, you could face fines or prosecution.
Are there any dangerous goods that cannot be shipped at all?
Yes. Certain substances are forbidden for transport under any circumstances: for example, some types of explosive that do not have an approved transport classification. Others are forbidden by specific modes. Many substances that can travel by sea are completely forbidden for air transport.
Who is legally responsible if I get the classification wrong?
You, as the shipper. The responsibility for correct classification, packaging, labelling, and documentation rests with the person who presents the goods for transport. Your freight forwarder can help, but they cannot take on your legal liability.
Does the quantity I am shipping make a difference?
Yes, significantly. Many regulations include quantity thresholds below which reduced requirements apply, or no requirements at all. This is known as “limited quantities” or “excepted quantities.” But the rules are specific to each class and mode, so always check before assuming a small quantity is exempt.
This article is for educational purposes. Regulations change regularly. Always check the current edition of the relevant regulations (IMDG Code, IATA DGR, ADR) or consult a qualified adviser before shipping dangerous goods.
This article is part of a learning path — return to explore more topics.
Keep reading
What is import customs clearance? Import customs clearance is the process of declaring goods to HMRC when they arrive in the UK, paying any applicable
What is FCL? FCL stands for Full Container Load. It means you book an entire shipping container, 20ft, 40ft, or 40ft High Cube, and no
What is an ATR1 certificate? An ATR1 certificate is a movement certificate used in trade between Turkey and countries within the EU Customs Union, and,
What is a T1 document? A T1 document is a customs transit document used to move goods that have not cleared customs through one or
What is CIF? Cost, Insurance and Freight (CIF) is an Incoterm where the seller pays for ocean freight and minimum cargo insurance to a named
What is DAP? DAP, Delivered at Place, is an Incoterm where the seller delivers goods to a named place of destination, ready for unloading, but