GHS hazard statement
H420: Harms public health and the environment by destroying ozone in the upper atmosphere
- H420
- Environmental hazards
- Warning
H420 means “Harms public health and the environment by destroying ozone in the upper atmosphere”. It is a GHS hazard statement for Hazardous to the ozone layer (Category 1), shown with GHS07 under the signal word “Warning”.
Hazard class and category
| Hazard class | Category | Pictogram | Signal word | UN transport class |
|---|---|---|---|---|
| Hazardous to the ozone layer | Category 1 |  | Warning | — |
What H420 means
Substances hazardous to the ozone layer are those which, on the evidence available, may endanger the structure or function of the stratospheric ozone layer.
Releasing the substance to the air can contribute to depletion of the ozone layer.
What to do
Avoid release to the atmosphere, recover or recycle as required by local rules, and dispose of it through approved channels.
This is general guidance for the hazard class. The safety data sheet for your product always takes precedence.
Precautionary statements for H420
The GHS lists these precautionary statements for this hazard. Which ones appear on a label depends on the supplier's classification.
| Code | Statement |
|---|---|
| P502 | Refer to manufacturer or supplier for information on recovery or recycling |
Chemicals carrying H420
1 chemical in our database. Classification comes from each chemical's primary GHS source, so a supplier's SDS may differ.
H420 frequently asked questions
What does H420 mean?
H420 means "Harms public health and the environment by destroying ozone in the upper atmosphere". It is a GHS hazard statement in the environmental hazards group, covering Hazardous to the ozone layer (Category 1).
Which pictogram goes with H420?
H420 is shown with GHS07 (Exclamation Mark).
What signal word goes with H420?
The signal word for H420 is "Warning".
Which precautionary statements go with H420?
The GHS data lists 1 precautionary statements for H420, including P502. They cover prevention, response, storage and disposal. The full list is on this page.
Hazard statements describe the hazard of a classified substance or mixture. The classification of a specific product can differ, so use the supplier's SDS.
https://pubchem.ncbi.nlm.nih.gov/ghs/ghscode_10.txt (UN GHS Revision 10, retrieved 2026-10-12)