Hstatements

H-statements, or hazard statements, are standardized phrases used under the Globally Harmonized System of Classification and Labelling of Chemicals (GHS) to describe the hazards of a substance or mixture. Each statement begins with the letter H followed by a three-digit number, for example H226 or H301, encoding specific hazard information. They are designed to be concise, machine-readable, and internationally applicable on product labels and Safety Data Sheets.

The statements cover physical hazards (for example H226: Flammable liquid), health hazards (for example H301: Toxic if swallowed; H315: Causes skin irritation; H317: May cause an allergic skin reaction; H335: May cause respiratory irritation), and environmental hazards (for example H400: Very toxic to aquatic life). This structure allows quick communication of risk and supports regulatory compliance across different jurisdictions.

The H-statements are part of the UN GHS framework and are adopted by many countries and regions, typically alongside precautionary statements (P-statements). They are periodically updated by the UN Sub-Committee of Experts and national authorities to reflect new scientific knowledge. On labels, H-statements may be accompanied by hazard pictograms and other safety information to provide comprehensive hazard communication.