2.2 Class 1 (Explosives) and Class 7 (Radioactive) Core Awareness

Class 1 (Explosives) and Class 7 (Radioactive) Core Awareness

Regulatory Notice: The ADR Basic Driver Training Certificate (Core Module) covers hazard identification, safety precautions, and emergency awareness for all nine classes. However, driving vehicles carrying commercial consignments of Class 1 (Explosives) or Class 7 (Radioactive Material) normally requires the relevant specialisation. Check ADR 8.2.1.4, the division 1.4S exception and applicable Class 7 exemptions, including the conditions of S12. Core awareness does not grant those endorsements.

1. Scope of the Core Module vs Specialization Endorsements

The ADR basic core qualification ensures drivers can recognize explosive and radioactive packages, understand their inherent dangers when operating on general freight transport units or shared terminals, and respond safely during an accident. However, drivers holding only the basic certificate are not authorised for specialist carriage merely by passing core. Some Class 7 exemptions use radiation/package conditions rather than the 1,000-point calculation.

For example, specialized Class 1 carriage requires in-depth training on EX/II and EX/III vehicle constructions, electrostatic grounding, and detailed Compatibility Group segregation. Specialized Class 7 transport demands rigorous knowledge of radiation dosimetry, transport index summation, contamination monitoring, and radioactive cargo securing.

2. Class 1: Explosive Substances and Articles

Class 1 encompasses solid or liquid substances (or mixtures) capable by chemical reaction of producing gas at such a temperature, pressure, and speed as to cause damage to the surroundings, as well as pyrotechnic substances and articles containing explosive materials.

The Six Explosive Divisions

Class 1 is divided into six numerical divisions based on the primary type and severity of hazard:

Compatibility Groups (A to S)

Because explosive substances interact unpredictably when combined, Class 1 items are assigned an alphabetical Compatibility Group from A through S (excluding letters I, M, O, P, Q, and R). The compatibility group indicates which explosive items can be safely transported together on the same vehicle:

• Group A: Primary explosive substance (extremely sensitive, e.g., lead azide).
• Group B: Article containing a primary explosive without effective protective features (e.g., detonators).
• Group C: Propellant explosive substance or secondary deflagrating explosive article.
• Group D: Secondary detonating explosive substance or black powder.
• Group E & F: Articles containing secondary detonating explosives with or without their own means of ignition.
• Group G: Pyrotechnic substance or article (flares, fireworks).
• Group S: Substance or article so packed or designed that any hazardous effects arising from accidental functioning are confined entirely within the package, unless the package has been degraded by fire.

The Special Case of Division 1.4S: Articles in Division 1.4, Compatibility Group S (such as small arms ammunition for personal firearms or life-saving distress flares) present such minimal risk that their transport is often exempt from full ADR placarding, orange plates, and specialized driver certificate requirements under ADR 1.1.3.6 (Transport Category 4: unlimited quantity without requiring an ADR driver card).

3. Class 7: Radioactive Material

Class 7 covers materials containing radionuclides where both the activity concentration and the total activity in the consignment exceed predetermined values specified in ADR 2.2.7.2.

Types of Ionizing Radiation

Drivers must understand the primary types of ionizing radiation emitted by Class 7 materials:

• Alpha (α) radiation: Consists of heavy helium nuclei. Low penetration power; stopped by a single sheet of paper or human dead skin. Poses catastrophic internal poisoning hazards if inhaled or ingested.
• Beta (β) radiation: High-speed electrons. Moderate penetration; stopped by a thin sheet of aluminum or thick clothing. Can cause skin burns and eye damage.
• Gamma (γ) radiation and X-rays: High-energy electromagnetic waves. Extreme penetration capability; requires thick lead, steel, or heavy concrete shielding to attenuate. Severe external irradiation hazard to the whole body.
• Neutron radiation: High-penetration uncharged particles emitted in specific nuclear fuel or research sources. Requires specialized hydrogenous shielding (water, paraffin wax).

Package Categories and the Transport Index (TI)

Class 7 packages are assigned to one of three categories based on the radiation level at the surface of the package and the Transport Index (TI):

Definition of Transport Index (TI): A dimensionless number derived by measuring the maximum radiation level at a distance of 1 meter from the external surfaces of the package in microsieverts per hour (µSv/h) and dividing by 10 (or directly reading the dose rate in millirem per hour). For example, a radiation reading of 30 µSv/h at 1 meter yields a TI of 3.0.

Vehicle Limits: For ordinary non-exclusive use transport units, the sum of Transport Indexes of all packages loaded onto a single vehicle must never exceed 50. Furthermore, the radiation level must not exceed 2,000 µSv/h at any point on the outer surface of the vehicle, and must not exceed 100 µSv/h at 2 meters from the vehicle sides.

Core Driver Emergency Actions for Class 7 Incidents

If a driver encounters an incident involving radioactive packages (e.g., collision, fire, rollover):

1. Evacuate and cordon: Establish a safety perimeter immediately. Do not approach damaged packages. Move away, keep others away from a safe position and follow emergency-services directions. ADR does not give drivers a universal 50-metre cordon for every Class 7 incident.
2. Position upwind: Stay upwind and uphill of any smoke, dust, or spilled liquid to prevent internal inhalation or contamination.
3. Never handle damaged packages: Do not touch, step on, or move compromised Class 7 packagings or spilled contents.
4. Notify emergency services: Call 112, clearly identifying the presence of Class 7 radioactive materials, quoting the UN numbers, categories, and TIs from the transport document. Request immediate dispatch of specialized radiation protection units.
5. Driver personal protection: Remember the three cardinal principles of radiation defense: Distance (maximize distance from the source), Time (minimize time spent near radiation), and Shielding (place vehicles, barriers, or earth embankments between yourself and the source).

Source check: 17 October 2026 — ADR 2025, English text published by the Slovak Ministry of Transport, 2.2.1, 2.2.7, 5.1.5 and CV33.