ADR Class 3 is the hazard class covering flammable liquids with a flash point of 60 °C or below. Petrol, ethanol, acetone, thinners and solvent-based paints and varnishes are typical examples. Diesel and light heating oil with a flash point between 60 and 100 °C are also included in this class as UN 1202. Substances are assigned to packing group I, II or III according to their flash point and boiling point.
By what criterion does a liquid fall into Class 3?
The decisive value is the flash point: the lowest temperature at which the vapour above the liquid's surface can be ignited by an ignition source. According to ADR 2.2.3, Class 3 covers the following groups:
- Liquids and liquid mixtures with a flash point not exceeding 60 °C,
- Diesel, gas oil and light heating oil with a flash point between 60 °C and 100 °C (UN 1202),
- Molten substances with a flash point above 60 °C that are carried at or above that temperature (UN 3256),
- Liquid desensitized explosives.
Liquids with a flash point above 35 °C that do not sustain combustion in the test in the UN Manual of Tests may fall outside Class 3. The value is given in section 9 of the safety data sheet; since the open-cup and closed-cup methods give different results, the closed-cup value accepted by ADR is used.
How are packing groups determined?
| Packing group | Criterion | Example |
|---|---|---|
| PG I (high danger) | Initial boiling point ≤ 35 °C | Diethyl ether (UN 1155) |
| PG II (medium danger) | Flash point < 23 °C, boiling point > 35 °C | Petrol (UN 1203), acetone (UN 1090), toluene (UN 1294) |
| PG III (low danger) | Flash point 23–60 °C, boiling point > 35 °C | Kerosene (UN 1223), diesel (UN 1202) |
The group directly changes the choice of packaging, the limited quantity limit and the exemption thresholds. The full concept is explained in the packing group entry.
What are the basic rules for transport in packages?
- The product is placed in UN-approved packaging (jerrican, drum, IBC) suitable for its packing group.
- Each package bears the UN number and label No. 3, which shows a flame symbol on a red background.
- The consignor prepares the transport document in accordance with ADR 5.4.1; for example, "UN 1263 PAINT, 3, II, (D/E)".
- For small inner packagings, the limited quantity rules may apply: for PG II substances the limit per inner packaging is usually 1 litre, and for PG III 5 litres.
- Under ADR 1.1.3.6, orange plates and an SRC5 (ADR driver training certificate) are not required for up to 333 litres per vehicle for PG II (transport category 2) and up to 1,000 litres for PG III (category 3); the transport document and a 2 kg fire extinguisher are still mandatory.
When products such as paint, thinners and sprays fall within the scope is covered separately in the paints and aerosols entry.
What changes in tanker transport?
Most fuel distribution is done by tanker, and the rules become stricter. If liquids with a flash point not exceeding 60 °C are carried in fixed or demountable tanks larger than 1 m³, the vehicle must be of type FL; diesel complying with EN 590 is exempt from this requirement and can be carried in an AT-type vehicle. The top line of the orange plate shows the Kemler code: 33 for petrol, 30 for diesel. In addition to the basic course, the driver's SRC5 certificate must include the tank module. Details are in the fuel tanker rules entry.
Common mistakes
- Treating solvent-based paint and thinners as "household products" and shipping them without labels.
- Sending an emptied but uncleaned tank as if it were an empty vehicle; the vapour is still dangerous and a transport document is required.
- Reading the flash point from the open-cup value and choosing the wrong packing group.
- Not adding the tunnel code (D/E for petrol) to the route plan.
How does Voltim Global support this?
Voltim Global holds the SQAS assessment used in chemical logistics (IDS; first issued 19.09.2025, valid until 19.09.2027). For a Class 3 load, the vehicle type is determined by the packing group and the total number of litres; therefore, in dangerous goods transport, the flash point and packing group should be confirmed from the safety data sheet before the shipment is planned.