ADR is the European agreement concerning the international carriage of dangerous goods by road. In practice it means this: once your cargo falls into one of the nine hazard classes, transport stops being a question of finding a vehicle. The vehicle, the driver, the packaging, the labelling and the paperwork each have to be compliant in their own right — and that compliance is settled at quotation stage, not on the loading bay.
This piece covers the practical side of ADR from a forwarder’s desk: which missing piece of data stops a quote, which exemption actually reduces the cost, and where these shipments get stuck.
The three data points needed before any price
There is no such thing as a ballpark figure on dangerous goods. The assessment always starts with three things:
- UN number. The four-digit code identifying the substance. It sits in section 14 of the safety data sheet.
- Class and subsidiary risk. Defines the type of hazard, and from it follow the vehicle, the segregation rules and the tunnel restriction.
- Packing group. I, II or III — the degree of danger, which sets the packaging standard.
All three are on the safety data sheet (SDS). Asking for a quote without attaching it usually costs a day.
The nine ADR classes
| Class | Covers | Typical difficulty in transport |
|---|---|---|
| 1 | Explosives | Special authorisations and route restrictions; many carriers decline outright |
| 2 | Gases (flammable, non-flammable, toxic) | Tank or cylinder equipment; tunnel category is decisive |
| 3 | Flammable liquids | The most shipped class: paints, solvents, alcohol-based products |
| 4 | Flammable solids and self-reactive substances | Humidity and temperature control |
| 5 | Oxidisers and organic peroxides | Strict segregation; temperature control may be required |
| 6 | Toxic and infectious substances | Cannot travel with foodstuffs on the same vehicle |
| 7 | Radioactive material | Separate authorisation and notification regime |
| 8 | Corrosives | Acids and bases; packaging compatibility governs |
| 9 | Miscellaneous dangerous goods | Includes lithium batteries and environmentally hazardous substances |
In practice most enquiries sit in classes 3, 8 and 9. On chemical sector shipments those three account for the bulk of the volume.
Limited and excepted quantities: the part that actually changes the cost
ADR provides relaxed regimes for certain substances carried in small inner packagings. Applied correctly, the same cargo moves at a much lower cost than under the full regime:
- Limited Quantity (LQ). Where the inner packaging stays below a defined threshold and the outer packaging complies, many ADR requirements do not apply. Pallets are marked with the LQ mark.
- Excepted Quantity (EQ). A lighter regime again for very small amounts; typical for samples and laboratory shipments.
- The 1.1.3.6 exemption (threshold per transport unit). Where the total quantity on board stays under the threshold for the applicable transport category, certain requirements fall away.
Whether these apply depends on packaging size and total quantity — that is, on the packing list. Without the packaging data, exemptions cannot be discussed.
Vehicle, driver and documents
| Element | Requirement |
|---|---|
| Driver | Valid ADR training certificate (scope varies by class) |
| Vehicle | Extinguishers, equipment kit, orange plates; tank movements also need a vehicle approval certificate |
| Company | An appointed dangerous goods safety adviser |
| Documents | The transport document must carry the UN number, proper shipping name, class, packing group and tunnel code |
| Packaging | UN-approved packaging with complete labels and markings |
Tunnel code: the detail that decides the route
Every ADR substance carries a tunnel restriction code, B to E. The code says which tunnel categories the load may not pass through. On European lanes this is not a technicality: across the Alpine crossings the code changes the route and therefore the transit time. It is why, when we quote, we also state the routing we intend to use.
Sea and air follow different rules
ADR applies to road only. The same substance falls under the IMDG Code at sea and IATA DGR by air, and the three sets of requirements do not line up. Packaging exempt on the road may be refused by air. On a multimodal shipment the preparation follows the most restrictive regime — settling that when the mode is chosen costs less than discovering it at the port. This is why we assess sea and air separately.
Six lines that speed up your enquiry
- Safety data sheet (SDS)
- UN number, class and packing group
- Inner packaging size and count (to assess LQ)
- Total net and gross weight
- Place of loading and place of delivery
- The Incoterms rule you want
Where the goods are chemicals, packaging, tank selection and paperwork go beyond the ADR class alone — the bulk liquid, IBC and drum breakdown is in our guide to chemical transport.
On an ADR movement the UN number, class and packing group must be entered correctly on the CMR consignment note; one missing line stops the vehicle at the border.
Frequently asked questions
Can dangerous goods move without ADR certification?
No. Where the movement falls under ADR, a valid driver training certificate, compliant vehicle equipment and a complete transport document are mandatory. The only exception is where a relaxed regime such as limited quantities applies and the relevant ADR requirements do not engage.
Do limited quantities apply to every product?
No. LQ depends on an inner packaging threshold set for each UN number, and for some substances it is not available at all. Applicability follows from the UN number and the packaging size; it is established, not estimated.
Can dangerous goods travel as part loads?
In most cases yes, but segregation rules apply: some classes cannot share a vehicle, and where the total on board exceeds the transport category thresholds the exemptions fall away. That is why on part-load ADR enquiries we also check what else is on the vehicle.
Is a safety adviser mandatory?
Appointing a dangerous goods safety adviser is required of undertakings that consign, carry, unload or pack dangerous goods. Exemption conditions depend on the activity and the quantities involved; it is an obligation on the business, not on the individual shipment.
Why are lithium batteries treated separately?
Because the same product produces a different UN number and different packaging requirements depending on how it travels: contained in equipment, packed with equipment, or alone. These are three distinct cases, and confusing them is the most common error we see.
How does insurance work on an ADR load?
Carrier liability is limited by weight, and damage arising from dangerous goods requires a specific clause in many policies. Cargo insurance is placed separately; on ADR loads the wording should be checked to confirm the cover extends to the product class.
Does customs require anything extra?
For declaration purposes being a dangerous good does not change the tariff classification, but some products need permits, licences or registrations. Because we run customs clearance with the same team that plans the transport, those checks happen before loading.
Send the safety data sheet and the packing list. From the UN number and the packaging data we will tell you whether an exemption applies, which routing we will use and what the real transit time is. Lane detail is on our road freight page; to start an enquiry use the quote form.