ADR Class 8 covers substances that, by chemical action, cause irreversible damage to skin or, in the event of leakage, corrode other goods and the vehicle. Sulphuric acid, hydrochloric acid, sodium hydroxide solution and acid-filled batteries are typical examples. Substances are assigned to packing group PG I, PG II or PG III according to how quickly they act on skin and metal.
Which substances fall under Class 8?
Under ADR 2.2.8.1.1, corrosives are substances that, by chemical action, cause irreversible damage to skin or, in the event of leakage, seriously damage other goods and the vehicle. Substances that form a corrosive liquid only on contact with water, or that give off corrosive vapour with moisture in the air, also fall into this class. The class is divided into classification codes:
- C1–C4: Acids (inorganic or organic, liquid or solid)
- C5–C8: Bases (alkalis)
- C9–C10: Other corrosives; C11: articles containing corrosives, such as batteries
- CF, CS, CW, CO, CT: Those that are additionally flammable, self-heating, emit flammable gas with water, oxidising or toxic
| UN No | Substance | Code / PG | Hazard No |
|---|---|---|---|
| 1830 | Sulphuric acid (more than 51% acid) | C1 / II | 80 |
| 1789 | Hydrochloric acid | C1 / II or III | 80 |
| 1824 | Sodium hydroxide solution | C5 / II or III | 80 |
| 2031 | Nitric acid (more than 70%) | CO1 / I, subsidiary hazard 5.1 | 885 |
| 2794 | Batteries, wet, filled with acid | C11 | 80 |
How to read codes such as 80, 88 and X80 on the orange plate is explained in the Kemler code entry.
How is the packing group determined?
The ADR 2.2.8.1 criteria assign the group according to how quickly irreversible damage occurs in intact skin tissue:
- PG I: Damage within an observation period of 60 minutes after an exposure of up to 3 minutes.
- PG II: Damage within an observation period of 14 days after an exposure of 3 to 60 minutes.
- PG III: Damage after an exposure of 60 minutes to 4 hours or, even without skin damage, corrosion of steel or aluminium at a rate of more than 6.25 mm per year at 55 °C.
Where there is no human experience, OECD test guidelines 404, 430, 431 and 435 are used. The effect of the group on packaging and exemptions is explained in the packing group entry.
What should be considered when choosing packaging?
ADR requires that the surface of the packaging in contact with the contents is not affected or weakened by them. In Class 8, this rule directly determines the choice of material: hydrofluoric acid etches glass, sodium hydroxide dissolves aluminium, and hydrochloric acid rapidly rusts uncoated steel. This is why HDPE jerricans, IBCs or lined tanks are preferred for most acids and bases. Plastic drums, jerricans and IBCs may be used for a maximum of 5 years from manufacture unless a shorter period is prescribed. How to read the packaging test code is explained in the UN-approved packaging entry.
What precautions are taken against leaks?
- Closure gaskets are checked before loading; jerricans are stacked closures up, following the orientation arrows.
- Acids and bases are not placed on the same pallet; for loading with other classes, the mixed loading rules are checked.
- The vehicle carries the personal protective equipment and eye-rinsing liquid specified in the instructions in writing.
- Empty but uncleaned packaging is treated in the same way as full packaging.
Common mistakes
Piling damaged used batteries on top of each other in an open crate, using second-hand IBCs whose chemical compatibility has not been checked, and omitting the subsidiary hazard of a Class 8 substance (for example 5.1 for nitric acid) from the documents are the most common mistakes.
How does Voltim Global support this?
For chemical cargo, Voltim Global is a company assessed under SQAS, the chemical industry's carrier assessment system. In the dangerous goods transport service, whether acids and bases can be planned in the same vehicle, the compatibility of packaging with its contents and the subsidiary hazard information in the documents are addressed when the shipment is planned.