According to the ADR (European Agreement concerning the International Carriage of Dangerous Goods by Road), dangerous goods are grouped into 9 classes. Classes 4, 5, and 6 are divided into subclasses, for a total of 13 (ADR 2.1.1.1).
- Class 1. Explosive substances and articles. Solid or liquid substances that, through a chemical reaction, can release gases at a temperature, pressure, and rate capable of causing damage to their surroundings, as well as the objects that contain them. This includes pyrotechnics.
- Class 2. Gases. Pure gases, gas mixtures, and objects containing them. A gas is defined as a substance that, at 50 °C, has a vapor pressure greater than 3 bar, or that, at 20 °C and a standard pressure of 101.3 kPa, is entirely gaseous.
- Class 3. Flammable liquids. Liquids with a flash point of 60 °C or less. Also, substances that are transported while hot at a temperature equal to or higher than their flash point.
- Class 4.1. Flammable solids, self-reactive substances, polymerizing substances, and desensitized solid explosives.
- Class 4.2. Substances liable to spontaneous combustion. They ignite or heat up upon contact with air, without any external energy source.
- Class 4.3. Substances that, when in contact with water, release flammable gases. These gases can form explosive mixtures with air.
- Class 5.1. Oxidizing substances. Although they are not necessarily combustible themselves, they can cause or promote the combustion of other materials, usually by releasing oxygen.
- Class 5.2. Organic peroxides. Substances derived from hydrogen peroxide. Some require temperature control during transport.
- Class 6.1. Toxic Substances. In small quantities and following a single or brief exposure, they can be harmful to health or cause death through inhalation, skin absorption, or ingestion.
- Class 6.2. Infectious substances. Substances that contain, or are believed to contain, pathogens (bacteria, viruses, parasites, fungi, prions, etc.) capable of causing disease in humans or animals.
- Class 7. Radioactive Materials. Materials containing radionuclides in amounts exceeding the activity limits established by the ADR.
- Class 8. Corrosive Substances. Due to their chemical action, they cause irreversible damage to the skin or, in the event of a leak, damage or destroy other goods or means of transport.
- Class 9. Miscellaneous hazardous materials and objects. During transport, they pose a different hazard than those in other classes. For example, lithium batteries or substances that are hazardous to the environment.
Each dangerous good has its own UN number and class listed in Table A of Chapter 3.2 of the ADR. Based on this information, the packaging, labeling, documentation, and conditions of transport are determined.
Do you have questions about how to classify your products or whether your company needs a Dangerous Goods Safety Adviser? Read our article or contact us.