GHS hazard statement
H303: May be harmful if swallowed
- H303
- Health hazards
- Warning
H303 means “May be harmful if swallowed”. It is a GHS hazard statement for Acute toxicity, oral (Category 5) under the signal word “Warning”.
Hazard class and category
| Hazard class | Category | Pictogram | Signal word | UN transport class |
|---|---|---|---|---|
| Acute toxicity, oral | Category 5 | None | Warning | — |
What H303 means
Acute toxicity covers harmful effects that occur after a single exposure, or several exposures within 24 hours, by swallowing (oral), skin contact (dermal) or breathing in (inhalation). The GHS has five categories, from Category 1 (most toxic) to Category 5, based on lethal-dose or lethal-concentration data.
The product can cause serious harm, and in the worst categories death, after one short exposure. Categories 1 to 3 carry the skull-and-crossbones pictogram, and Category 4 carries the exclamation mark.
What to do
Avoid all contact, breathing and swallowing. Use only with good ventilation or local exhaust, wear the gloves, protective clothing and respiratory protection the SDS calls for, do not eat, drink or smoke while working, wash thoroughly afterwards, and call a poison center or doctor if exposed.
This is general guidance for the hazard class. The safety data sheet for your product always takes precedence.
Precautionary statements for H303
The GHS lists these precautionary statements for this hazard. Which ones appear on a label depends on the supplier's classification.
| Code | Statement |
|---|---|
| P301+P317 | IF SWALLOWED: Get medical help. |
Chemicals carrying H303
No chemicals in our database are classified with H303 yet.
H303 frequently asked questions
What does H303 mean?
H303 means "May be harmful if swallowed". It is a GHS hazard statement in the health hazards group, covering Acute toxicity, oral (Category 5).
Which pictogram goes with H303?
H303 does not require a GHS pictogram in the data we compile.
What signal word goes with H303?
The signal word for H303 is "Warning".
Which precautionary statements go with H303?
The GHS data lists 1 precautionary statements for H303, including P301+P317. 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)