Self reactive substances are thermally unstable liquids or solids liable to undergo a strongly exothermic thermal decomposition even without participation of oxygen (air). This definition excludes materials classified under the GHS as explosive, organic peroxides, or as oxidizing. These materials may have similar properties, but such hazards are addressed in their specific endpoints.
Substances and mixtures of this hazard class are assigned to one of seven ‘Types’
- Detonates partially, does not deflagrate rapidly and show no violent effect when heated under confinement
- Does not detonate at all, deflagrates slowly and show no violent effect when heated under confinement
- Does not detonate or deflagrate at all and shows a medium effect when heated under confinement
Pyrophorics
A pyrophoric liquid is a liquid which, even in small quantities, is liable to ignite within five minutes after coming into contact with air. Substances and mixtures of this hazard class are assigned to a single hazard category.
Pyrophoric Solids
A solid which, even in small quantities, is liable to ignite within five minutes after coming into contact with air.
Self-Heating Substances
A solid or liquid, other than a pyrophoric substance, which, by reaction with air and without energy supply, is liable to self-heat. This endpoint differs from a pyrophoric substance in that it will ignite only when in large amounts (kilograms) and after long periods of time (hours or days). Substances and mixtures of this hazard class are assigned to one of two hazard categories
Emits Flammable Gas
Substances which, in contact with water, emit flammable gases are solids or liquids which, by interaction with water, are liable to become spontaneously flammable or to give off flammable gases in dangerous quantities. Substances in this category are assigned to one of three hazard categories
Substances which Emit Flammable Gases in Contact with Water
- Detonates partially, does not deflagrate rapidly and show no violent effect when heated under confinement
- Does not detonate at all, deflagrates slowly and show no violent effect when heated under confinement
- Does not detonate or deflagrate at all and shows a medium effect when heated under confinement
Explosives
An explosive substance (or mixture) is a solid or liquid which is in itself capable by chemical reaction of producing gas at such a temperature and pressure and at such a speed as to cause damage to the surroundings. Pyrotechnic substances are included even when they do not evolve gases. A pyrotechnic substance (or mixture) is designed to produce an effect by heat, light, sound, gas or smoke, or a combination of these as the result of non-detonative, self-sustaining, exothermic chemical reactions.
Substances, mixtures, and articles are assigned to one of six divisions depending on the type of hazard they present.