GHS Hazard Statements (H-Codes)
A hazard statement is the standard sentence on a label that tells you what is hazardous about a chemical and how serious it is. This index lists all89 current GHS hazard statements, grouped into physical, health and environmental hazards, with the hazard class, category and signal word behind each one. Select a code for what it means, what to do, and the chemicals that carry it.
Codes marked "Deleted" appear in the data we compile but are no longer part of the current GHS revision (5 in total). They are shown for reference because you may meet them on older labels and SDSs.
Physical hazards (42)
H200–H299: hazards from the physical properties of a chemical, such as fire, explosion, pressure and corrosion to metals.
| Code | Statement | Hazard class and category | Signal word |
|---|---|---|---|
| H200 | Unstable Explosive Deleted | Explosives — Unstable Explosive | Danger |
| H201 | Explosive; mass explosion hazard Deleted | Explosives — Div 1.1 | Danger |
| H202 | Explosive; severe projection hazard Deleted | Explosives — Div 1.2 | Danger |
| H203 | Explosive; fire, blast or projection hazard Deleted | Explosives — Div 1.3 | Danger |
| H204 | Fire or projection hazard | Explosives — Category 2B Explosives — Category 2C | Warning |
| H205 | May mass explode in fire Deleted | Explosives — Div 1.5 | Danger |
| H206 | Fire, blast or projection hazard; increased risk of explosion if desensitizing agent is reduced | Desensitized explosives — Category 1 | Danger |
| H207 | Fire or projection hazard; increased risk of explosion if desensitizing agent is reduced | Desensitized explosives — Category 2 Desensitized explosives — Category 3 | Danger |
| H208 | Fire hazard; increased risk of explosion if desensitizing agent is reduced | Desensitized explosives — Category 4 | Warning |
| H209 | Explosive | Explosives — Category 1 Explosives — Category 2A | Danger |
| H210 | Very sensitive | Explosives — Category 1 | Danger |
| H211 | Maybe sensitive | Explosives — Category 1 | Danger |
| H220 | Extremely flammable gas | Flammable gases — 1A: Flammable gas, Pyrophoric gas, Chemically unstable gas A,B | Danger |
| H221 | Flammable gas | Flammable gases — 1B Flammable gases — Category 2 | Danger |
| H222 | Extremely flammable aerosol | Aerosols — Category 1 | Danger |
| H223 | Flammable aerosol | Aerosols — Category 2 | Warning |
| H224 | Extremely flammable liquid and vapor | Flammable liquids — Category 1 | Danger |
| H225 | Highly Flammable liquid and vapor | Flammable liquids — Category 2 | Danger |
| H226 | Flammable liquid and vapor | Flammable liquids — Category 3 | Warning |
| H227 | Combustible liquid | Flammable liquids — Category 4 | Warning |
| H228 | Flammable solid | Flammable solids — Category 1 Flammable solids — Category 2 | Danger |
| H229 | Pressurized container: may burst if heated | Aerosols — Category 1 Aerosols — Category 2 Aerosols — Category 3 | Danger |
| H230 | May react explosively even in the absence of air | Flammable gases — 1A, Chemically unstable gas A | Danger |
| H231 | May react explosively even in the absence of air at elevated pressure and/or temperature | Flammable gases — 1A, Chemically unstable gas B | Danger |
| H232 | May ignite spontaneously if exposed to air | Flammable gases — 1A, Pyrophoric gas | Danger |
| H240 | Heating may cause an explosion | Self-reactive substances and mixtures; Organic peroxides — Type A | Danger |
| H241 | Heating may cause a fire or explosion | Self-reactive substances and mixtures; Organic peroxides — Type B | Danger |
| H242 | Heating may cause a fire | Self-reactive substances and mixtures; Organic peroxides — Type C, D Self-reactive substances and mixtures; Organic peroxides — Type E, F | Danger |
| H250 | Catches fire spontaneously if exposed to air | Pyrophoric liquids — Category 1 Pyrophoric solids — Category 1 | Danger |
| H251 | Self-heating; may catch fire | Self-heating substances and mixtures — Category 1 | Danger |
| H252 | Self-heating in large quantities; may catch fire | Self-heating substances and mixtures — Category 2 | Warning |
| H260 | In contact with water releases flammable gases which may ignite spontaneously | Substances and mixtures which in contact with water, emit flammable gases — Category 1 | Danger |
| H261 | In contact with water releases flammable gas | Substances and mixtures which in contact with water, emit flammable gases — Category 2 Substances and mixtures which in contact with water, emit flammable gases — Category 3 | Danger |
| H270 | May cause or intensify fire; oxidizer | Oxidizing gases — Category 1 | Danger |
| H271 | May cause fire or explosion; strong Oxidizer | Oxidizing liquids; Oxidizing solids — Category 1 | Danger |
| H272 | May intensify fire; oxidizer | Oxidizing liquids; Oxidizing solids — Category 2 Oxidizing liquids; Oxidizing solids — Category 3 | Danger |
| H280 | Contains gas under pressure; may explode if heated | Gases under pressure — Compressed gas, Liquefied gas, Dissolved gas | Warning |
| H281 | Contains refrigerated gas; may cause cryogenic burns or injury | Gases under pressure — Refrigerated liquefied gas | Warning |
| H282 | Extremely flammable chemical under pressure: may explode if heated | Chemicals under pressure — Category 1 | Danger |
| H283 | Flammable chemical under pressure: may explode if heated | Chemicals under pressure — Category 2 | Warning |
| H284 | Chemical under pressure: may explode if heated | Chemicals under pressure — Category 3 | Warning |
| H290 | May be corrosive to metals | Corrosive to Metals — Category 1 | Warning |
Health hazards (44)
H300–H399: harm to people through swallowing, skin or eye contact, or inhalation, including toxicity, corrosion, sensitization, cancer and reproductive effects.
| Code | Statement | Hazard class and category | Signal word |
|---|---|---|---|
| H300 | Fatal if swallowed | Acute toxicity, oral — Category 1, 2 | Danger |
| H301 | Toxic if swallowed | Acute toxicity, oral — Category 3 | Danger |
| H302 | Harmful if swallowed | Acute toxicity, oral — Category 4 | Warning |
| H303 | May be harmful if swallowed | Acute toxicity, oral — Category 5 | Warning |
| H304 | May be fatal if swallowed and enters airways | Aspiration hazard — Category 1 | Danger |
| H305 | May be harmful if swallowed and enters airways | Aspiration hazard — Category 2 | Warning |
| H310 | Fatal in contact with skin | Acute toxicity, dermal — Category 1, 2 | Danger |
| H311 | Toxic in contact with skin | Acute toxicity, dermal — Category 3 | Danger |
| H312 | Harmful in contact with skin | Acute toxicity, dermal — Category 4 | Warning |
| H313 | May be harmful in contact with skin | Acute toxicity, dermal — Category 5 | Warning |
| H314 | Causes severe skin burns and eye damage | Skin corrosion/irritation — Category 1, 1A, 1B, 1C | Danger |
| H315 | Causes skin irritation | Skin corrosion/irritation — Category 2 | Warning |
| H316 | Causes mild skin irritation | Skin corrosion/irritation — Category 3 | Warning |
| H317 | May cause an allergic skin reaction | Sensitization, Skin — Category 1, 1A, 1B | Warning |
| H318 | Causes serious eye damage | Serious eye damage/eye irritation — Category 1 | Danger |
| H319 | Causes serious eye irritation | Serious eye damage/eye irritation — Category 2A | Warning |
| H320 | Causes eye irritation | Serious eye damage/eye irritation — Category 2B | Warning |
| H330 | Fatal if inhaled | Acute toxicity, inhalation — Category 1, 2 | Danger |
| H331 | Toxic if inhaled | Acute toxicity, inhalation — Category 3 | Danger |
| H332 | Harmful if inhaled | Acute toxicity, inhalation — Category 4 | Warning |
| H333 | May be harmful if inhaled | Acute toxicity, inhalation — Category 5 | Warning |
| H334 | May cause allergy or asthma symptoms or breathing difficulties if inhaled | Sensitization, respiratory — Category 1, 1A, 1B | Danger |
| H335 | May cause respiratory irritation | Specific target organ toxicity, single exposure; Respiratory tract irritation — Category 3 | Warning |
| H336 | May cause drowsiness or dizziness | Specific target organ toxicity, single exposure; Narcotic effects — Category 3 | Warning |
| H340 | May cause genetic defects | Germ cell mutagenicity — Category 1, 1A, 1B | Danger |
| H341 | Suspected of causing genetic defects | Germ cell mutagenicity — Category 2 | Warning |
| H350 | May cause cancer | Carcinogenicity — Category 1, 1A, 1B | Danger |
| H350i | May cause cancer by inhalation | Carcinogenicity — Category 1, 1A, 1B | Danger |
| H351 | Suspected of causing cancer | Carcinogenicity — Category 2 | Warning |
| H360 | May damage fertility or the unborn child | Reproductive toxicity — Category 1, 1A, 1B | Danger |
| H360F | May damage fertility | Reproductive toxicity — Category 1, 1A, 1B | Danger |
| H360D | May damage the unborn child | Reproductive toxicity — Category 1, 1A, 1B | Danger |
| H360FD | May damage fertility; May damage the unborn child | Reproductive toxicity — Category 1, 1A, 1B | Danger |
| H360Fd | May damage fertility; Suspected of damaging the unborn child | Reproductive toxicity — Category 1, 1A, 1B | Danger |
| H360Df | May damage the unborn child; Suspected of damaging fertility | Reproductive toxicity — Category 1, 1A, 1B | Danger |
| H361 | Suspected of damaging fertility or the unborn child | Reproductive toxicity — Category 2 | Warning |
| H361f | Suspected of damaging fertility | Reproductive toxicity — Category 2 | Warning |
| H361d | Suspected of damaging the unborn child | Reproductive toxicity — Category 2 | Warning |
| H361fd | Suspected of damaging fertility; Suspected of damaging the unborn child | Reproductive toxicity — Category 2 | Warning |
| H362 | May cause harm to breast-fed children | Reproductive toxicity, effects on or via lactation — Additional category | No signal word |
| H370 | Causes damage to organs | Specific target organ toxicity, single exposure — Category 1 | Danger |
| H371 | May cause damage to organs | Specific target organ toxicity, single exposure — Category 2 | Warning |
| H372 | Causes damage to organs through prolonged or repeated exposure | Specific target organ toxicity, repeated exposure — Category 1 | Danger |
| H373 | May causes damage to organs through prolonged or repeated exposure | Specific target organ toxicity, repeated exposure — Category 2 | Warning |
Environmental hazards (8)
H400–H499: hazards to the aquatic environment and, in some systems, to the ozone layer.
| Code | Statement | Hazard class and category | Signal word |
|---|---|---|---|
| H400 | Very toxic to aquatic life | Hazardous to the aquatic environment, acute hazard — Category 1 | Warning |
| H401 | Toxic to aquatic life | Hazardous to the aquatic environment, acute hazard — Category 2 | No signal word |
| H402 | Harmful to aquatic life | Hazardous to the aquatic environment, acute hazard — Category 3 | No signal word |
| H410 | Very toxic to aquatic life with long lasting effects | Hazardous to the aquatic environment, long-term hazard — Category 1 | Warning |
| H411 | Toxic to aquatic life with long lasting effects | Hazardous to the aquatic environment, long-term hazard — Category 2 | No signal word |
| H412 | Harmful to aquatic life with long lasting effects | Hazardous to the aquatic environment, long-term hazard — Category 3 | No signal word |
| H413 | May cause long lasting harmful effects to aquatic life | Hazardous to the aquatic environment, long-term hazard — Category 4 | No signal word |
| H420 | Harms public health and the environment by destroying ozone in the upper atmosphere | Hazardous to the ozone layer — Category 1 | Warning |
Combined hazard statements (17)
Combined statements merge two or more single statements into one sentence to save label space, for example when a substance is hazardous by more than one route of exposure.
| Code | Statement | Hazard class and category | Signal word |
|---|---|---|---|
| H300+H310 | Fatal if swallowed or in contact with skin | Acute toxicity, oral; acute toxicity, dermal — Category 1, 2 | Danger |
| H300+H330 | Fatal if swallowed or if inhaled | Acute toxicity, oral; acute toxicity, inhalation — Category 1, 2 | Danger |
| H310+H330 | Fatal in contact with skin or if inhaled | Acute toxicity, dermal; acute toxicity, inhalation — Category 1, 2 | Danger |
| H300+H310+H330 | Fatal if swallowed, in contact with skin or if inhaled | Acute toxicity, oral; acute toxicity, dermal; acute toxicity, inhalation — Category 1, 2 | Danger |
| H301+H311 | Toxic if swallowed or in contact with skin | Acute toxicity, oral; acute toxicity, dermal — Category 3 | Danger |
| H301+H331 | Toxic if swallowed or if inhaled | Acute toxicity, oral; acute toxicity, inhalation — Category 3 | Danger |
| H311+H331 | Toxic in contact with skin or if inhaled. | Acute toxicity, dermal; acute toxicity, inhalation — Category 3 | Danger |
| H301+H311+H331 | Toxic if swallowed, in contact with skin or if inhaled | Acute toxicity, oral; acute toxicity, dermal; acute toxicity, inhalation — Category 3 | Danger |
| H302+H312 | Harmful if swallowed or in contact with skin | Acute toxicity, oral; acute toxicity, dermal — Category 4 | Warning |
| H302+H332 | Harmful if swallowed or if inhaled | Acute toxicity, oral; acute toxicity, inhalation — Category 4 | Warning |
| H312+H332 | Harmful in contact with skin or if inhaled | Acute toxicity, dermal; acute toxicity, inhalation — Category 4 | Warning |
| H302+H312+H332 | Harmful if swallowed, in contact with skin or if inhaled | Acute toxicity, oral; acute toxicity, dermal; acute toxicity, inhalation — Category 4 | Warning |
| H303+H313 | May be harmful if swallowed or in contact with skin | Acute toxicity, oral; acute toxicity, dermal — Category 5 | Warning |
| H303+H333 | May be harmful if swallowed or if inhaled | Acute toxicity, oral; acute toxicity, inhalation — Category 5 | Warning |
| H313+H333 | May be harmful in contact with skin or if inhaled | Acute toxicity, dermal; acute toxicity, inhalation — Category 5 | Warning |
| H303+H313+H333 | May be harmful if swallowed, in contact with skin or if inhaled | Acute toxicity, oral; acute toxicity, dermal; acute toxicity, inhalation — Category 5 | Warning |
| H315+H320 | Cause skin and eye irritation | Skin corrosion/irritation and serious eye damage/eye irritation — Category 2, 2B | Warning |
Looking for the advice that goes with a hazard? See the precautionary statements. To learn how the hazards are categorised, see the hazard classes, and for the symbols, the pictograms.
Frequently asked questions
What is an H-code?
An H-code is the identifier of a GHS hazard statement, a standard sentence that describes the nature and severity of a chemical hazard. The letter H stands for hazard, and the three digits are an index number. H2xx codes are physical hazards, H3xx are health hazards and H4xx are environmental hazards.
What do combined H-codes like H300+H310 mean?
A combined code merges two or more statements that would otherwise appear together on a label into one sentence, for example H300+H310 for "Fatal if swallowed or in contact with skin". The label may print the combined sentence instead of the separate ones.
Does a higher H-number mean a more serious hazard?
No. The number is only an index. Severity comes from the hazard class and category, and from the signal word and pictogram that go with the statement.
https://pubchem.ncbi.nlm.nih.gov/ghs/ghscode_10.txt (UN GHS Revision 10, retrieved 2026-10-12)