DGR Class 4 — Flammable Solids

DGR Class 4 — Flammable Solids is a dangerous goods classification divided into three sub-classes: Class 4.1 (flammable solids, self-reactive substances and solid desensitized explosives), Class 4.2 (substances liable to spontaneous combustion), and Class 4.3 (substances which, in contact with water, emit flammable gases). All kinds of combustible solid items sent through air transport are governed by the IATA Class 4 Dangerous Goods Regulations. Classes 4.1, 4.2 and 4.3 have been assigned a packing group which indicates the degree of danger: Packing Group I (substances presenting high danger), Packing Group II (substances presenting medium danger), and Packing Group III (substances presenting low danger).

A FedEx Express shipment carries AWB number 023-87654321 containing safety matches classified as UN1944, Class 4.1, Packing Group III, shipped from Memphis International Airport (MEM) to Frankfurt Airport (FRA). An Emirates SkyCargo shipment with AWB prefix 176-45678923 transports white phosphorus under UN1381, Class 4.2, Packing Group I from Dubai International Airport (DXB) to London Heathrow (LHR) under strict temperature-controlled conditions.

• Class 4
• flammable solids cargo
• spontaneously combustible

What are the three sub-classes of DGR Class 4 — Flammable Solids and their key differences?

Class 4.1 covers flammable solids like matches and sulfur that ignite easily, Class 4.2 includes spontaneously combustible materials like phosphorus that ignite without external ignition sources, and Class 4.3 contains substances like calcium carbide that emit flammable gases when wet. Each sub-class requires different handling procedures and packing groups (I, II, or III) based on danger level.

Which packing group applies to common DGR Class 4 — Flammable Solids like matches and phosphorus?

Safety matches are typically classified as Packing Group III (low danger), while white phosphorus requires Packing Group I (high danger) classification. Metal powders vary between Packing Groups II and III depending on particle size and combustion characteristics. The specific packing group determines packaging requirements and quantity limitations per IATA DGR Section 4.2.