Medius International Logistics

Dangerous goods classes (IMO / ADR / IATA)

The 9 classes of dangerous goods, their labels, packing groups and the documents you need in transport. See which rules apply by sea, air and road on one page.

Hazard classes

1

Class 1 – Explosives

Substances and articles that can explode by producing sudden gas, heat and pressure through a chemical reaction. The division is followed by a compatibility group letter A–S (e.g. 1.4S).

  • 1.1 Mass explosion hazard1.11
    1.1 · Mass explosion hazardExplosion affecting almost the entire load instantly.
  • 1.2 Projection hazard1.21
    1.2 · Projection hazardProjection hazard without mass explosion.
  • 1.3 Fire hazard1.31
    1.3 · Fire hazardFire hazard with minor blast or projection hazard.
  • 1.4 No significant hazard1.41
    1.4 · No significant hazardEffects largely confined to the package.
  • 1.5 Very insensitive substances1.51
    1.5 · Very insensitive substancesVery insensitive substances with a mass explosion hazard.
  • 1.6 Extremely insensitive articles1.61
    1.6 · Extremely insensitive articlesExtremely insensitive articles without a mass explosion hazard.

Examples: Fireworks, ammunition, signal flares, airbag inflators, detonators

2

Class 2 – Gases

Compressed, liquefied, dissolved under pressure or refrigerated liquefied gases, and aerosols.

  • 2.1 Flammable gases2
    2.1 · Flammable gasesGases that ignite when mixed with air (e.g. propane, butane, flammable aerosols).
  • 2.2 Non-flammable, non-toxic gases2
    2.2 · Non-flammable, non-toxic gasesGases presenting a pressure hazard (e.g. nitrogen, carbon dioxide, helium).
  • 2.3 Toxic gases2
    2.3 · Toxic gasesGases toxic or corrosive when inhaled (e.g. chlorine, ammonia).

Examples: Aerosol sprays, LPG, propane, oxygen and nitrogen cylinders, fire extinguishers, refrigerant gases

3

Class 3 – Flammable liquids

Liquids with a flash point of 60 °C or below. The packing group depends on the flash point and initial boiling point.

  • 3 Flammable liquids3
    Flammable liquidsPG I: initial boiling point ≤ 35 °C · PG II: flash point < 23 °C · PG III: flash point 23–60 °C

Examples: Paint, varnish, thinner, perfume, alcohol, petrol, ink, adhesives

4

Class 4 – Flammable solids

Readily combustible solids, substances liable to spontaneous combustion and substances that emit flammable gas in contact with water.

  • 4.1 Flammable solids4
    4.1 · Flammable solidsReadily combustible solids, self-reactive substances and solid desensitized explosives.
  • 4.2 Spontaneously combustible4
    4.2 · Spontaneously combustibleSubstances that heat up and ignite spontaneously in contact with air.
  • 4.3 Dangerous when wet4
    4.3 · Dangerous when wetSubstances that emit flammable gas in contact with water.

Examples: Matches, sulphur, metal powders, activated carbon, calcium carbide, sodium

5

Class 5 – Oxidizers and organic peroxides

Substances that cause or intensify the combustion of other materials, generally by yielding oxygen.

  • 5.1 Oxidizing substances5.15.1
    5.1 · Oxidizing substancesSubstances that, while not necessarily combustible, can cause or accelerate combustion.
  • 5.2 Organic peroxides5.25.2
    5.2 · Organic peroxidesHeat-sensitive substances that can decompose rapidly; some require temperature control.

Examples: Hydrogen peroxide, ammonium nitrate fertilisers, calcium hypochlorite, peroxide hardeners

6

Class 6 – Toxic and infectious substances

Substances that can cause death or serious harm if swallowed, inhaled or by skin contact, and substances containing pathogens.

  • 6.1 Toxic substances6
    6.1 · Toxic substancesSubstances harmful to health even in small quantities.
  • 6.2 Infectious substances6
    6.2 · Infectious substancesSubstances known or expected to contain pathogens.

Examples: Pesticides, some dyes and chemicals, medical and clinical waste, diagnostic specimens

7

Class 7 – Radioactive material

Material emitting ionizing radiation. The label category (I-White, II-Yellow, III-Yellow) depends on surface radiation level and transport index.

  • 7 Radioactive material7
    Radioactive materialLabel category: I-White, II-Yellow or III-Yellow.

Examples: Medical isotopes, industrial gauges, some smoke detector sources

8

Class 8 – Corrosive substances

Substances that by chemical action severely damage living tissue or corrode metals.

  • 8 Corrosive substances8
    Corrosive substancesCorrosive to skin and metals.

Examples: Battery acid, sulphuric and hydrochloric acid, sodium hydroxide (caustic soda), some cleaning products

9

Class 9 – Miscellaneous dangerous goods

Substances that present a hazard in transport but do not fall under the other classes. Lithium batteries use a separate dedicated label (9A); environmentally hazardous substances can fall in this class.

  • 9 Miscellaneous dangerous goods9
    Miscellaneous dangerous goodsLithium batteries use the separate 9A label.

Examples: Lithium batteries and devices containing them, dry ice, vehicles and engines, environmentally hazardous substances, some magnetized material (air)

Labels are illustrative; actual labels must follow the sizes and designs in the regulations.

Packing groups (PG)

The packing group shows the degree of danger and sets the required strength of the packaging. No packing group is assigned to classes 1, 2 and 7, divisions 5.2 and 6.2, or to self-reactive substances in 4.1.

  1. I
    High danger

    Requires the strongest packaging (marked X).

  2. II
    Medium danger

    Packaging marked X or Y may be used.

  3. III
    Low danger

    Packaging marked X, Y or Z may be used.

Limited and excepted quantities (LQ / EQ)

Some dangerous goods in small inner packagings can travel under simpler rules as “limited quantities” (LQ) or “excepted quantities” (EQ). Package marking and declaration are still required, and air transport has its own LQ rules.

Documents and marks required

Safety data sheet (SDS / MSDS)
A 16-section sheet from the manufacturer. Transport information is in section 14: UN number, proper shipping name, class, packing group and marine pollutant status.
Dangerous goods declaration (DGD)
Signed by the shipper. By sea the IMO form, by air the IATA “Shipper’s Declaration for Dangerous Goods”, by road the ADR transport document.
Container / vehicle packing certificate
By sea, certifies that the dangerous goods were packed and secured in the container according to the rules (Container Packing Certificate).
UN-approved packaging
The packaging carries the UN mark, packaging type, X/Y/Z performance letter and manufacturing details.
Labels and placards
Packages carry hazard labels, the UN number and proper shipping name; containers carry large placards on all four sides, road vehicles orange plates.
Marine pollutant mark
Environmentally hazardous substances carry the mark with a fish and a tree.

Rules by mode of transport

Sea – IMDG Code

Published by the IMO and amended regularly. Segregation rules in container stowage, emergency schedules (EmS, e.g. F-E, S-D) and carrier approval are key; each shipping line may have its own acceptance conditions.

Air – IATA DGR

Based on the ICAO Technical Instructions and updated every year. Some goods are forbidden on passenger aircraft and may only fly on cargo aircraft (CAO); some cannot fly at all. Quantity limits apply per package.

Road – ADR

Updated by UNECE every two years. Vehicles need orange plates and equipment, drivers an ADR training certificate (SRC5 in Turkey). Tunnel restriction codes can affect the route.

Rail – RID

Largely aligned with ADR. On rail-linked routes such as the Middle Corridor, the requirements of the countries along the route also apply.

Points to note in Turkey

  • Companies that ship, carry or pack dangerous goods may need a Dangerous Goods Activity Certificate (TMFB) from the Ministry of Transport and Infrastructure.
  • Companies in scope must work with a Dangerous Goods Safety Adviser (TMGD).
  • Rules and exemptions depend on quantity and activity; confirm current legislation with your adviser.

What to prepare for a dangerous goods quote

  • Current SDS / MSDS (with section 14 completed)
  • UN number and proper shipping name
  • Class, any subsidiary hazard and packing group
  • Flash point (for class 3)
  • Whether it is a marine pollutant
  • Packaging type, inner packaging quantity, total net and gross weight
  • Number and dimensions of packages
  • Whether it will ship as a limited quantity (LQ)
Request a dangerous goods quote

This page is for general information and does not replace the regulations. Classification and packing are the shipper’s responsibility; for every shipment the current IMDG Code, IATA DGR or ADR text and the SDS apply.

Frequently asked questions

How many classes of dangerous goods are there?

Under the UN Recommendations, dangerous goods are divided into 9 classes: explosives, gases, flammable liquids, flammable solids, oxidizers and organic peroxides, toxic and infectious substances, radioactive material, corrosives and miscellaneous dangerous goods. The IMDG Code, IATA DGR and ADR use the same classification.

What is a UN number?

A UN number is a four-digit code assigned by the UN to a substance or group of substances (e.g. UN 1263 paint). It identifies the goods on documents, packages and vehicles.

Are lithium batteries dangerous goods?

Yes. Lithium-ion and lithium metal batteries are in class 9 (e.g. UN 3480, UN 3481, UN 3090, UN 3091) and are subject to particularly strict rules by air.

Are perfume and paint dangerous goods?

Most perfumes, paints, varnishes and thinners are flammable liquids in class 3. The exact classification follows section 14 of the product’s SDS.

What is the difference between IMDG, IATA DGR and ADR?

All three are based on the UN classification but cover different modes: the IMDG Code covers sea, IATA DGR air and ADR road. Quantity limits, packaging and documentation requirements differ by mode.

Let's plan your shipment

Share your cargo details and we will prepare the right route and price for you.

Get a quote