GHS H-Statements: Complete Guide to All Hazard Statement Codes
Hazard statements — commonly called H-statements or H-codes — are standardised phrases that describe the hazards of a chemical substance or mixture. Every H-code is assigned a unique number and a fixed text that cannot be altered.
What Are H-Statements?
Under GHS and CLP, an H-statement is an alphanumeric code (e.g. H301) paired with a fixed phrase (“Toxic if swallowed”). H-statements appear on chemical labels and in Section 2 of the Safety Data Sheet.
The codes are structured as follows:
- H2xx — Physical hazards
- H3xx — Health hazards
- H4xx — Environmental hazards
H2xx: Physical Hazard Statements
| Code | Statement |
|---|---|
| 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 |
| H220 | Extremely flammable gas |
| H221 | Flammable gas |
| H222 | Extremely flammable aerosol |
| H223 | Flammable aerosol |
| H224 | Extremely flammable liquid and vapour |
| H225 | Highly flammable liquid and vapour |
| H226 | Flammable liquid and vapour |
| H228 | Flammable solid |
| H229 | Pressurised 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 in large quantities; 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; oxidiser |
| H271 | May cause fire or explosion; strong oxidiser |
| H272 | May intensify fire; oxidiser |
| H280 | Contains gas under pressure; may explode if heated |
| H281 | Contains refrigerated gas; may cause cryogenic burns or injury |
| H290 | May be corrosive to metals |
H3xx: Health Hazard Statements
| Code | Statement |
|---|---|
| H300 | Fatal if swallowed |
| H301 | Toxic if swallowed |
| H302 | Harmful if swallowed |
| H304 | May be fatal if swallowed and enters airways |
| H310 | Fatal in contact with skin |
| H311 | Toxic in contact with skin |
| H312 | Harmful in contact with skin |
| H314 | Causes severe skin burns and eye damage |
| H315 | Causes skin irritation |
| H317 | May cause an allergic skin reaction |
| H318 | Causes serious eye damage |
| H319 | Causes serious eye irritation |
| H330 | Fatal if inhaled |
| H331 | Toxic if inhaled |
| H332 | 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 |
| H351 | Suspected of causing cancer |
| H360 | May damage fertility or the unborn child |
| H361 | Suspected of damaging fertility or 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 |
H4xx: Environmental Hazard Statements
| Code | Statement |
|---|---|
| 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 |
Supplemental Hazard Statements (EU Only)
CLP uses additional EUH-statements for hazards not fully covered by GHS:
| Code | Statement |
|---|---|
| EUH001 | Explosive when dry |
| EUH006 | Explosive with or without contact with air |
| 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 |
| 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 |
How H-Statements Are Assigned
H-statements are not chosen by manufacturers — they are determined by the hazard classification. The classification process:
- Collect all available data (LD50, LC50, flash point, etc.)
- Compare against GHS classification criteria (cut-off values, categories)
- Assign the hazard category
- The H-statement follows automatically from the category
For mixtures, classification may use bridging principles or the ATE additivity formula.
H-Statements on Labels vs SDS
On the label: All applicable H-statements must appear, but CLP allows combining statements where appropriate (e.g. H300 + H310 + H330 may be combined as “Fatal if swallowed, in contact with skin or if inhaled”).
In the SDS (Section 2): H-statements are listed individually with their codes. Combining is not used in the SDS.
Searching H-Statements by Substance
Use our H-Statements Reference to look up all hazard codes for any substance in the CLP Annex VI database, including signal words and associated pictograms.
Related Resources
- GHS Signal Words: Danger vs Warning — which H-codes trigger each signal word
- GHS P-Statements Guide — precautionary codes that pair with H-statements
- GHS vs OSHA HCS 2024 — updated H-statement requirements for US compliance
- P-Statements Reference →
Reference: UN GHS Rev.9, Chapters 2–4. CLP Regulation (EC) No 1272/2008, Annex III. OSHA HCS 29 CFR 1910.1200, Appendix C.