Division 4.1 — Flammable solids
Readily combustible solids, self-reactive substances and desensitised explosives.
Carrier acceptance
The published default for this class. A UN-specific rule can override it — lithium batteries and dry ice are both Class 9 and are treated quite differently.
| Carrier | Ground | Air | Position |
|---|---|---|---|
| UPS | contract required | contract required | Flammable solids accepted under the hazmat agreement. |
| FedEx | contract required | contract required | Flammable solids require dangerous goods approval. |
| USPS | restricted | prohibited | Flammable solids are mailable by surface only within Publication 52 limits. |
| Amazon FBA | review required | restricted | Flammable solids accepted after dangerous goods review. |
Carrier positions encode each carrier's published default as of the ruleset date. Tariffs change more often than regulations, and a contracted shipper may hold different terms — confirm against the carrier's current guide before the first shipment of a new item.
Encoded entries (3)
| UN | Proper shipping name | Class | PG | Labels | Air |
|---|---|---|---|---|---|
| UN1944 | Matches, safety | 4.1 | III | FLAMMABLE SOLID | pax forbidden·cargo forbidden |
| UN1325 | Flammable solid, organic, n.o.s. | 4.1 | none | FLAMMABLE SOLID | pax limited·cargo permitted |
| UN1350 | Sulfur | 4.1 | III | FLAMMABLE SOLID | pax limited·cargo permitted |
Classify a specific product in this class
The class alone does not give you a shipping paper. Send the actual product to POST /api/classify and you get the UN number, the proper shipping name, the packing group and every carrier position for that specific item.
Questions
- What is Division 4.1 — Flammable solids?
- Readily combustible solids, self-reactive substances and desensitised explosives.
- Does Division 4.1 — Flammable solids have a packing group?
- Yes for most entries. Packing group I is the highest danger, II medium, III low. Where an entry's packing group depends on a measured property (a flash point for Class 3, a concentration for Class 8), Classify7 asks for that figure rather than assuming one.
- Can I ship Division 4.1 — Flammable solids by air?
- UPS: contract required; FedEx: contract required; USPS: prohibited; Amazon FBA: restricted. These are published carrier defaults, not regulatory limits — a contracted shipper may hold different terms, and the regulation may permit what the carrier declines.