Hazard Class 8 — Corrosive Substances
Acids, bases, battery electrolyte, paint strippers and other substances that attack skin or metal.
Overview
Class 8 covers substances that, by chemical action, cause irreversible damage to skin or significantly corrode steel or aluminium at defined rates. Packing groups I, II and III reflect the severity and contact time required to cause damage.
Many Class 8 substances carry subsidiary risks — for example, oleum (UN1831) carries a Class 6.1 subsidiary risk in addition to its Class 8 primary risk.
Aviation context
Class 8 is one of the most common classes in aviation MRO. Battery electrolyte for wet cells (UN2794 acid, UN2795 alkali), paint strippers, descaling agents and many specialised cleaners fall under Class 8.
Battery shipments are a frequent acceptance issue: a sealed lead-acid battery may travel as UN2800 (non-spillable) under specific provisions, while a flooded wet battery is fully regulated under UN2794.
Typical UN numbers in aviation MRO
| UN Number | Proper Shipping Name | Notes |
|---|---|---|
| UN2794 | Batteries, wet, filled with acid (8) | Flooded lead-acid batteries |
| UN2795 | Batteries, wet, filled with alkali (8) | Nickel-cadmium aviation batteries |
| UN2800 | Batteries, wet, non-spillable (8) | Sealed valve-regulated lead-acid |
| UN1760 | Corrosive liquid, n.o.s. (8) | Generic — PG depends on severity |
| UN1830 | Sulphuric acid (8, PG II) | Battery electrolyte concentrate |
Packaging and marking essentials
- Inner packagings must resist the corrosive substance for the duration of transport. Wrong material choice is a frequent leak source.
- Wet batteries require protection against short circuit and against electrolyte spill — terminals must be insulated and the battery positioned to prevent leakage.
- Subsidiary-risk labels must be applied when the substance carries one (e.g. 6.1 toxic, 5.1 oxidiser).
Frequently Asked Questions
Can I ship a Ni-Cad aviation battery by air?
Yes — UN2795 is permitted under specific packing instructions on both passenger and cargo aircraft, provided the battery is properly secured, terminals insulated, and the packaging meets the Class 8 requirements for wet alkali batteries.
What makes a battery 'non-spillable' under UN2800?
A non-spillable battery is constructed so that no free electrolyte will escape when subjected to defined vibration and differential-pressure tests. It must be marked 'NON-SPILLABLE' or 'NON-SPILLABLE BATTERY' and meet the additional provisions in the IATA DGR special provisions.
Need to classify a specific part?
DG Copilot identifies the UN number, hazard class and air transport status from a part number — in seconds.
Other hazard classes
This information is provided for guidance only. Always verify against the current IATA DGR edition. Final classification and DGD must be validated by a certified DG specialist.