ADR Class 3: Flammable Liquids
We see these types of liquids every day in gas stations or do-it-yourself stores. The best known are gasoline, varnishes, adhesives or aircraft kerosene. According to ADR regulations, flammable liquids are those that:
- Its melting point is less than or equal to 20ºC at an atmospheric pressure of 101.3kPa. For viscous materials to which we cannot assign a melting point, the fluidity test (penetrometer test) shall be applied.
- At 50ºC they have a vapor pressure equal to or less than 300kPa (3 bar) and are not completely gaseous at 20ºC and at the standard pressure of 101.3kPa.
- Its flash point is less than or equal to 60ºC.
Also included are flammable liquids and solids at ambient temperature but which, when transported, reach a temperature equal to or higher than their flash point (above 60ºC). These substances are normally assigned to UN number 3256.
Desensitized explosive materials
Class 3 of the ADR regulation also includes liquid desensitized explosive substances. These materials are prepared in a homogeneous liquid mixture, either in solution or in suspension in water, and are free of explosive properties.
Class 3 Divisions
The materials and objects of class 3 are subdivided into:
- F: Flammable liquids with no subsidiary danger
- F1: Flammable liquids with a flash point less than or equal to 60ºC.
- F2: Flammable liquids with a flash point above 60ºC, transported or delivered at or above the flash point.
- FT
- FT1: Toxic flammable liquids
- FT2: Pesticides
- FC: Corrosive flammable liquids
- FTC: Flammable, toxic and corrosive liquids
- D: Desensitized flammable explosive liquids
- FC: Corrosive flammable liquids
- FTC: Flammable, toxic and corrosive liquids
- D: Desensitized flammable explosive liquids
Packaging groups
Flammable liquids should be assigned to packing groups according to the degree of danger they pose for transport.
| Packing group | Flash point | Boiling point |
|---|---|---|
| I | … | ≤ 35ºC |
| II | <23 | >35ºC |
| III | ≤23ºC and ≤60ºC | >>35ºC |
Personal protective equipment for Class 3
When handling ADR Class 3 materials, you must be properly equipped to be prepared for any incident that may occur. The necessary equipment is:
- Face shield
- Respiratory protection equipment, both nasal and facial.
Static electricity is generated during the transfer of flammable liquids and its formation is unavoidable. The accumulation of electrostatic charges is the sum of two components and dissipation is the ability of matter to recombine itself without generating potential hazards.
- Antistatic protective gloves
- Antistatic chemical body protection
When handling materials with a flash point equal to or lower than 61ºC, the installation must have the correct electrical conductivity. Equipotential bonding and grounding must be in place throughout the plant to dissipate electrical charges and return them to ground, minimizing potential hazards.
Package labeling
Pressurized chemicals are assigned to the following groups according to their hazardous properties:
Flammable viscous liquids such as paints, enamels, lacquers, varnishes or adhesives with a flash point below 23°C may be included in packing group III if the following conditions are met:
- In the solvent separation test, the separated solvent layer is less than 3%.
- The mixture does not contain any substance presenting a primary or secondary hazard of Division 6.1 or Class 8.
- That the capacity of the container used does not exceed 450 liters.
- That the viscosity and flash point conform to the following table:
| Flow time t (s) | Nozzle diameter (mm) | Flash point (ºC) |
|---|---|---|
| 20<t≤60< td=””></t≤60<> | 4 | Greater than 17 |
| 60<t≤100< td=””></t≤100<> | 4 | Greater than 10 |
| 20<t≤32< td=””></t≤32<> | 6 | Higher than 5 |
| 32<t≤44< td=””></t≤44<> | 6 | Greater than -1 |
| 44<t≤100< td=””></t≤100<> | 6 | Greater than -5 |
| 100<t< td=””></t<> | 6 | -5 or lower |
Viscous liquids are not subject to any provisions of the ADR regulations if they are transported in single or combined containers of a capacity of 5 liters or less and provided that the containers comply with general provisions 4.1.1, 4.1.2 and 4.1.1.1.4 to 4.1.1.1.8.
2.2.3.1.7: “While applying the test procedures for both flash point and viscosity and accepting the flammability criteria of Class 3 for a solution or mixture expressly mentioned or containing the principal material mentioned in Table 3A, it may be that the solution or mixture is not subject to the present provisions of Class 3”.
