Class 1 materials that can undergo rapid chemical reactions, releasing significant amounts of gas, heat, and pressure. These reactions can result in explosions, posing serious risks during transport and handling.

Class 2, Division 2.1 gases that easily ignite and burn when they are exposed to an ignition source. These gases are highly flammable and so they pose significant fire risks during handling and transport.

Class 2, Division 2.2 gases that do not easily ignite or burn. These are the gases that lack flammability and are typically used where the fire hazards must be minimized, so making them safer to transport.

Class 3 liquids that easily ignite and burn when exposed to an ignition source. With a flash point of 60°C (140°F) or lower, these liquids present significant fire and explosion hazards during transport.

Class 4, Division 4.1 solids that can easily ignite and burn through the friction, heat, or small ignition sources. These materials burn quickly, so posing significant fire risks during handling and transport.

Class 4, Division 4.3 materials that react dangerously when exposed to water. These substances can produce flammable gases, toxic fumes, or explosions upon contact with water, posing severe risks.

Class 4, Division 4.2 materials that ignite without an external ignition source. These substances self-heat due to chemical reactions with air, or they may combust spontaneously when exposed to oxygen.

Class 5, Division 5.1 materials that release oxygen or other oxidizing agents, causing or enhancing the combustion of other materials. Oxidizers mainly accelerate the burning of flammable substances.

Class 5, Division 5.2 organic compounds containing a peroxide group (-O-O-). These highly reactive materials may decompose and release oxygen, posing fire and explosion risks due to their instability.

Class 6, Division 6.1 gases that can cause severe harm or death if inhaled, ingested, or absorbed through the skin. These substances are highly toxic, posing serious health risks even at low concentrations.

Class 6, Division 6.2 materials capable of causing disease in humans or animals. These substances contain pathogens, such as bacteria, viruses, or fungi, which can cause infections or disease when exposed.

A label for packages with radioactive materials emitting very low levels of radiation. This label is part of the system that identifies radiation levels in transported materials, indicating the lowest level.

Class 8 substances that cause severe damage to living tissue or materials through chemical reactions. These substances can destroy skin on contact and corrode metals, posing risks during transport and use.

Miscellaneous Dangerous Goods. Class 9 includes materials that don’t fit other hazard classes but still pose risks. Though less hazardous, these substances still require special handling during transport.