Hazardous substances classification codes

Find out which classification codes mean and which ones, if any, apply to your hazardous substances.

Under the HSNO Act, a hazardous substance is any substance that has one or more of the following properties above specified levels:

  • an explosive nature (including fireworks)
  • flammability
  • ability to oxidise (i.e. accelerate a fire)
  • corrosiveness
  • acute or chronic toxicity (toxic to humans)
  • ecotoxicity, with or without bioaccumulation (i.e. can kill living things either directly or by building up in the environment)
  • can generate a hazardous substance on contact with air or water.

Hazardous substances can have more than one hazardous property. For example, methylated spirits and petrol are flammable and toxic.

Below find the hazardous substance classification used in New Zealand under the HSNO Act, grouped into physical, health and environmental hazards, and with a classification number assigned to each type of hazard. In the related content on our other pages, there is useful information on how to measure the hazardous properties of a substance.

If the substance has any hazardous properties, then it is a hazardous substance under the HSNO Act. If it doesn't have any hazardous properties, then the substance can be considered non-hazardous and you don't need to worry about approval under the HSNO Act.

If you are importing or manufacturing it yourself, you must determine whether it is hazardous. If you are given a safety data sheet for the substance, it may give information about whether the substance should be considered hazardous.

Physical hazards Plus
Explosive 
1.1 Substances and articles that have a mass explosion hazard
1.2 Substances and articles that have a projection hazard but not a mass explosion hazard
1.3 Substances and articles that have a fire hazard and either a minor blast hazard or a minor projection hazard, or both, but not a mass explosion hazard
1.4 Substances and articles that present no significant explosive hazard
1.5 Very insensitive substances that have a mass explosion hazard
1.6 Extremely insensitive articles that do not have a mass explosion hazard
Flammable gas and aerosol 
2.1.1A Flammable gas - high hazard
2.1.1B Flammable gas - medium hazard
2.1.2A Flammable aerosol
Flammable liquid 
3.1A Flammable liquid - very high hazard
3.1B Flammable liquid - high hazard
3.1C Flammable liquid - medium hazard
3.1D Flammable liquid - low hazard
Readily combustible solids, self-reactive substances and desensitised explosives 
4.1.1A Readily combustible solids and solids that may cause fire through friction: medium hazard
4.1.1B Readily combustible solids and solids that may cause fire through friction: low hazard
4.1.2A Self-reactive substances: type A
4.1.2B Self-reactive substances: type B
4.1.2C Self-reactive substances: type C
4.1.2D Self-reactive substances: type D
4.1.2E Self-reactive substances: type E
4.1.2F Self-reactive substances: type F
4.1.2G Self-reactive substances: type G
4.1.3A Solid desensitised explosives: high hazard
4.1.3B Solid desensitised explosives: medium hazard
4.1.3C Solid desensitised explosives: low hazard
Spontaneously combustible substances and solids that emit flammable gas 
4.2A Spontaneously combustible substances: pyrophoric substances: high hazard
4.2B Spontaneously combustible substances: self-heating substances: medium hazard
4.2C Spontaneously combustible substances: self-heating substances: low hazard
4.3A Solids that emit flammable gas when in contact with water: high hazard
4.3B Solids that emit flammable gas when in contact with water: medium hazard
4.3C Solids that emit flammable gas when in contact with water: low hazard
Oxidising substances
5.1.1A Oxidising substances that are liquids or solids: high hazard
5.1.1B Oxidising substances that are liquids or solids: medium hazard
5.1.1C Oxidising substances that are liquids or solids: low hazard
5.1.2A Oxidising substances that are gases
Organic peroxides
5.2A Organic peroxides: type A
5.2B Organic peroxides: type B
5.2C Organic peroxides: type C
5.2D Organic peroxides: type D
5.2E Organic peroxides: type E
5.2F Organic peroxides: type F
5.2G Organic peroxides: type G
Health hazards Plus
Acutely toxic
6.1A Substances that are acutely toxic - Fatal
6.1B Substances that are acutely toxic - Fatal
6.1C Substances that are acutely toxic - Toxic
6.1D Substances that are acutely toxic - Harmful
6.1E Substances that are acutely toxic – May be harmful, aspiration hazard
Skin irritant
6.3A Substances that are irritating to the skin
6.3B Substances that are mildly irritating to the skin
Eye irritant
6.4A Substances that are irritating to the eye
Sensitisation
6.5A Substances that are respiratory sensitisers
6.5B Substances that are contact sensitisers
Mutagens 
6.6A Substances that are known or presumed human mutagens
6.6B Substances that are suspected human mutagens
Carcinogens 
6.7A Substances that are known or presumed human carcinogens
6.7B Substances that are suspected human carcinogens 
Reproductive/developmental toxicants 
6.8A Substances that are known or presumed human reproductive or developmental toxicants
6.8B Substances that are suspected human reproductive or developmental toxicants
6.8C Substances that produce toxic human reproductive or developmental effects on or via lactation
Target organ toxicants 
6.9A Substances that are toxic to human target organs or systems
6.9B Substances that are harmful to human target organs or systems
Metal corrosive 
8.1A Substances that are corrosive to metals
Skin corrosive 
8.2A Substances that are corrosive to dermal tissue (UN PGI)
8.2B Substances that are corrosive to dermal tissue (UN PGII)
8.2C Substances that are corrosive to dermal tissue (UN PGIII)
Eye corrosive 
8.3A Substances that are corrosive to ocular tissue
Environmental hazards Plus
Aquatic ecotoxic
9.1A Substances that are very ecotoxic in the aquatic environment
9.1B Substances that are ecotoxic in the aquatic environment
9.1C Substances that are harmful in the aquatic environment
9.1D Substances that are slightly harmful to the aquatic environment or are otherwise designed for biocidal action
Soil ecotoxic
9.2A Substances that are very ecotoxic in the soil environment
9.2B Substances that are ecotoxic in the soil environment
9.2C Substances that are harmful in the soil environment
9.2D Substances that are slightly harmful in the soil environment
Terrestrial vertebrate ecotoxic
9.3A Substances that are very ecotoxic to terrestrial vertebrates
9.3B Substances that are ecotoxic to terrestrial vertebrates
9.3C Substances that are harmful to terrestrial vertebrates
Terrestrial invertebrate exotoxic
9.4A Substances that are very ecotoxic to terrestrial invertebrates
9.4B Substances that are ecotoxic to terrestrial invertebrates
9.4C Substances that are harmful to terrestrial invertebrates