Hazard statements form part of the Globally Harmonized System of Classification and Labelling of Chemicals (GHS). They are intended to form a set of standardized phrases about the hazards of chemical substances and mixtures that can be translated into different languages.^[1]^[2] As such, they serve the same purpose as the well-known R-phrases, which they are intended to replace.

Hazard statements are one of the key elements for the labelling of containers under the GHS, along with:^[3]

an identification of the product
one or more hazard pictograms (where necessary)
a signal word – either Danger or Warning – where necessary
precautionary statements, indicating how the product should be handled to minimize risks to the user (as well as to other people and the general environment)
the identity of the supplier (who might be a manufacturer or importer).

Each hazard statement is designated a code, starting with the letter H and followed by three digits. Statements which correspond to related hazards are grouped together by code number, so the numbering is not consecutive. The code is used for reference purposes, for example to help with translations, but it is the actual phrase which should appear on labels and safety data sheets.^[4]

Physical hazards

H-phrases Physical Hazards^[5]
Code	Phrase
H200	Unstable explosive
H201	Explosive: mass explosion hazard
H202	Explosive: severe projection hazard
H203	Explosive: fire, blast or projection hazard
H204	Fire or projection hazard
H205	May mass explode in fire
H206	Fire, blast or projection hazard: increased risk of explosion if desensitizing agent is reduced
H207	Fire or projection hazard; increased risk of explosion if desensitizing agent is reduced
H208	Fire hazard; increased risk of explosion if desensitizing agent is reduced
H209	Explosive
H210	Very sensitive
H211	May be sensitive
H220	Extremely flammable gas
H221	Flammable gas
H222	Extremely flammable material
H223	Flammable material
H224	Extremely flammable liquid and vapour
H225	Highly flammable liquid and vapour
H226	Flammable liquid and vapour
H227	Combustible liquid
H228	Flammable solid
H229	Pressurized container: may burst if heated
H230	May react explosively even in the absence of air
H231	May react explosively even in the absence of air at elevated pressure and/or temperature
H240	Heating may cause an explosion
H241	Heating may cause a fire or explosion
H242	Heating may cause a fire
H250	Catches fire spontaneously if exposed to air
H251	Self-heating: may catch fire
H252	Self-heating in large quantities: may catch fire
H260	In contact with water releases flammable gases which may ignite spontaneously
H261	In contact with water releases flammable gas
H270	May cause or intensify fire: oxidizer
H271	May cause fire or explosion: strong oxidizer
H272	May intensify fire: OXIDISER
H280	Contains gas under pressure: may explode if heated
H281	Contains refrigerated gas: may cause cryogenic burns or injury
H282	Extremely flammable chemical under pressure: May explode if heated
H283	Flammable chemical under pressure: May explode if heated
H284	Chemical under pressure: May explode if heated
H290	May be corrosive to metals

Health hazards

H-phrases Health Hazards^[5]
Code	Phrase
H300	Fatal if swallowed
H300+H310	Fatal if swallowed or in contact with skin
H300+H310+H330	Fatal if swallowed, in contact with skin or if inhaled
H300+H330	Fatal if swallowed or if inhaled
H301	Toxic if swallowed
H301+H311	Toxic if swallowed or in contact with skin
H301+H311+H331	Toxic if swallowed, in contact with skin or if inhaled
H301+H331	Toxic if swallowed or if inhaled
H302	Harmful if swallowed
H302+H312	Harmful if swallowed or in contact with skin
H302+H312+H332	Harmful if swallowed, in contact with skin or if inhaled
H302+H332	Harmful if swallowed or inhaled
H303	May be harmful if swallowed
H303+H313	May be harmful if swallowed or in contact with skin
H303+H313+H333	May be harmful if swallowed, in contact with skin or if inhaled
H303+H333	May be harmful if swallowed or if inhaled
H304	May be fatal if swallowed and enters airways
H305	May be harmful if swallowed and enters airways
H310	Fatal in contact with skin
H310+H330	Fatal in contact with skin or if inhaled
H311	Toxic in contact with skin
H311+H331	Toxic in contact with skin or if inhaled
H312	Harmful in contact with skin
H312+H332	Harmful in contact with skin or if inhaled
H313	May be harmful in contact with skin
H313+H333	May be harmful in contact with skin or if inhaled
H314	Causes severe skin burns and eye damage
H315	Causes skin irritation
H315+H320	Causes skin and eye irritation
H316	Causes mild skin irritation
H317	May cause an allergic skin reaction
H318	Causes serious eye damage
H319	Causes serious eye irritation
H320	Causes eye irritation
H330	Fatal if inhaled
H331	Toxic if inhaled
H332	Harmful if inhaled
H333	May be harmful if inhaled
H334	May cause allergy or asthma symptoms or breathing difficulties if inhaled
H335	May cause respiratory irritation
H336	May cause drowsiness or dizziness
H340	May cause genetic defects
H341	Suspected of causing genetic defects
H350	May cause cancer
H350i	May cause cancer by inhalation
H351	Suspected of causing cancer
H360	May damage fertility or the unborn child
H360D	May damage the unborn child
H360Df	May damage the unborn child. Suspected of damaging fertility.
H360F	May damage fertility
H360FD	May damage fertility. May damage the unborn child.
H360Fd	May damage fertility. Suspected of damaging the unborn child.
H361	Suspected of damaging fertility or the unborn child
H361d	Suspected of damaging the unborn child
H361f	Suspected of damaging fertility
H361fd	Suspected of damaging fertility. Suspected of damaging the unborn child.
H362	May cause harm to breast-fed children
H370	Causes damage to organs
H371	May cause damage to organs
H372	Causes damage to organs through prolonged or repeated exposure
H373	May cause damage to organs through prolonged or repeated exposure

Environmental hazards

H-phrases Environmental Hazards^[5]
Code	Phrase
H400	Very toxic to aquatic life
H401	Toxic to aquatic life
H402	Harmful to aquatic life
H410	Very toxic to aquatic life with long lasting effects
H411	Toxic to aquatic life with long lasting effects
H412	Harmful to aquatic life with long lasting effects
H413	May cause long lasting harmful effects to aquatic life
H420	Harms public health and the environment by destroying ozone in the upper atmosphere
H441	Very toxic to terrestrial invertebrates

Country-specific hazard statements

European Union

The European Union has implemented the GHS through the CLP Regulation. Nevertheless, the older system based on the Dangerous Substances Directive was used in parallel until June 2015. Some R-phrases which do not have simple equivalents under the GHS have been retained under the CLP Regulation:^[6] the numbering mirrors the number of the previous R-phrase.

Physical properties

EUH006: Explosive with or without contact with air, deleted in the fourth adaptation to technical progress of CLP.
EUH014: Reacts violently with water
EUH018: In use may form flammable/explosive vapour-air mixture
EUH019: May form explosive peroxides
EUH044: Risk of explosion if heated under confinement

Health properties

EUH029: Contact with water liberates toxic gas
EUH031: Contact with acids liberates toxic gas
EUH032: Contact with acids liberates very toxic gas
EUH066: Repeated exposure may cause skin dryness or cracking
EUH070: Toxic by eye contact
EUH071: Corrosive to the respiratory tract
EUH380: May cause endocrine disruption in humans
EUH381: Suspected of causing endocrine disruption in humans

Environmental properties

EUH059: Hazardous to the ozone layer, superseded by GHS Class 5.1 in the second adaptation to technical progress of CLP.
EUH430: May cause endocrine disruption in the environment
EUH431: Suspected of causing endocrine disruption in the environment
EUH440: Accumulates in the environment and living organisms including in humans
EUH441: Strongly accumulates in the environment and living organisms including in humans
EUH450: Can cause long-lasting and diffuse contamination of water resources
EUH451: Can cause very long-lasting and diffuse contamination of water resources

Other EU hazard statements

Some other hazard statements intended for use in very specific circumstances have also been retained under the CLP Regulation.^[7] In this case, the numbering of the EU specific hazard statements can coincide with GHS hazard statements if the "EU" prefix is not included.

EUH201: Contains lead. Should not be used on surfaces liable to be chewed or sucked by children.
- EUH201A: Warning! Contains lead.
EUH202: Cyanoacrylate. Danger. Bonds skin and eyes in seconds. Keep out of the reach of children.
EUH203: Contains chromium(VI). May produce an allergic reaction.
EUH204: Contains isocyanates. May produce an allergic reaction.
EUH205: Contains epoxy constituents. May produce an allergic reaction.
EUH206: Warning! Do not use together with other products. May release dangerous gases (chlorine).
EUH207: Warning! Contains cadmium. Dangerous fumes are formed during use. See information supplied by the manufacturer. Comply with the safety instructions.
EUH208: Contains <name of sensitising substance>. May produce an allergic reaction.
EUH209: Can become highly flammable in use.
- EUH209A: Can become flammable in use.
EUH210: Safety data sheet available on request.
EUH211: Warning! Hazardous respirable droplets may be formed when sprayed. Do not breathe spray or mist.
EUH401: To avoid risks to human health and the environment, comply with the instructions for use.

Australia

The GHS was adopted in Australia from 1 January 2012 and becomes mandatory in States and Territories that have adopted the harmonised Work Health and Safety laws (other than Victoria and Western Australia) as of 1 January 2017.^[8] The National Code of Practice for the Preparation of Safety Data Sheets for Hazardous Chemicals ^[9] includes 12 Australian-specific GHS Hazard Statements, as follows:

Physical hazard statements

AUH001: Explosive without moisture
AUH006: Explosive with or without contact with air
AUH014: Reacts violently with water
AUH018: In use, may form a flammable/explosive vapor-air mixture
AUH019: May form explosive peroxides
AUH044: Risk of explosion if heated under confinement

Human health hazard statements

AUH029: Contact with water liberates toxic gas
AUH031: Contact with acids liberates toxic gas

Additional non-GHS hazard statements

AUH032: Contact with acids liberates very toxic gas
AUH066: Repeated exposure may cause skin dryness or cracking
AUH070: Toxic by eye contact
AUH071: Corrosive to the respiratory tract

New Zealand

As of March 2009, the relevant New Zealand regulations under the Hazardous Substances and New Organisms Act 1996 do not specify the exact wording required for hazard statements. However, the New Zealand classification system includes three categories of environmental hazard which are not included in the GHS Rev.2:

Ecotoxicity to soil environment
Ecotoxicity to terrestrial vertebrates
Ecotoxicity to terrestrial invertebrates

These are classes 9.2–9.4 respectively of the New Zealand classification scheme, and are divided into subclasses according to the degree of hazard.^[10] Substances in subclass 9.2D ("Substances that are slightly harmful in the soil environment") do not require a hazard statement, while substances in the other subclasses require an indication of the general degree of hazard and general type of hazard.^[11]