Globally Harmonized System (GHS) is the United Nations framework for classifying chemical hazards and communicating them through standard labels, pictograms and 16-section safety data sheets, adopted in the US through OSHA's HazCom standard.
The Globally Harmonized System of Classification and Labelling of Chemicals (GHS) is a United Nations framework that sets common criteria for classifying chemical hazards and a standard format for communicating them on labels and safety data sheets. It is not a law in itself. Countries adopt it, in whole or in part, through their own regulations.
Before GHS, a solvent shipped from Germany to Texas to Brisbane might be classed as toxic in one country and not in another, with different symbols and wording on each label. GHS gives everyone the same rules for deciding what a hazard is and the same building blocks for describing it. The UN updates the text roughly every two years in numbered revisions, and each country picks which revision to adopt and when.
OSHA brought GHS into US workplaces through the Hazard Communication Standard (HCS), 29 CFR 1910.1200. The 2012 update aligned the HCS with GHS Revision 3 and replaced the old free-form material safety data sheets with the standard 16-section format. OSHA published another update on May 20, 2024, aligning the HCS with GHS Revision 7 and adding provisions such as revised rules for small container labels and for labeling packaged containers that have been released for shipment.
In January 2026, OSHA extended the 2024 rule's compliance dates by four months. Under the revised schedule, manufacturers, importers and distributors had until May 19, 2026 to update labels and SDSs for substances, and have until November 19, 2027 for mixtures. Employers must update workplace labeling, written programs and training by November 20, 2026 for substances and May 19, 2028 for mixtures. Check osha.gov for any further changes before planning around these dates.
Under the model WHS laws, Australia has required GHS Revision 7 for classifying and labeling hazardous chemicals since January 1, 2023. Canada implements GHS through WHMIS and the Hazardous Products Regulations. The EU and UK use the CLP Regulation, which includes the environmental hazard classes that OSHA does not enforce.
A compliant shipped-container label under the HCS carries six elements:
GHS defines nine pictograms: flame, flame over circle, exploding bomb, gas cylinder, corrosion, skull and crossbones, exclamation mark, health hazard and environment. OSHA requires the first eight. The environment pictogram (a dead fish and tree) is optional on US labels because environmental hazards fall outside OSHA's jurisdiction. Suppliers selling into Canada, Australia or Europe often include it anyway, and its presence on a US label is not a violation.
Under GHS, each hazard class is split into categories, and a lower number means a more severe hazard. Category 1 flammable liquids are more dangerous than Category 4. This is the reverse of some older rating systems, such as the NFPA 704 diamond, where 4 is the most severe. Mixing the two up during training is a common source of confusion. For how flammability categories map to flash point and boiling point, see flammable liquids.
GHS fixes the order of the SDS so that workers and responders can find the same information in the same place on any sheet. Sections 1 through 11 and 16 are mandatory content under the HCS. Sections 12 through 15 (ecological, disposal, transport and regulatory information) must appear, but OSHA does not enforce their content because those topics belong to other agencies.
The full structure is covered under safety data sheet.
A building materials plant mixed an epoxy floor coating in-house and decanted it from 200-liter drums into one-gallon pails for its installation crews. The pails carried only a hand-written product name. When an installer developed skin sensitization after weeks of contact without gloves, the investigation found that nobody on the crew knew the resin was classed as a skin sensitizer, even though the supplier's drum label showed the exclamation mark and the health hazard pictograms.
The plant changed its secondary container practice. Every pail now carries a workplace label with the product identifier, the pictograms and the key hazard statements copied from the supplier label, printed from a template. Crew leads walk new hires through the drum label and Section 8 of the SDS before their first job. The chemical hazard inventory was updated to flag every product carrying a sensitizer classification.
Not always. OSHA lets employers label workplace containers with either the full shipped-container label or the product identifier plus words, pictures or symbols that convey the hazards, combined with the SDS and training. A portable container filled from a labeled container and meant only for the immediate use of the worker who filled it is exempt. In practice, printing the product name, signal word and pictograms avoids most questions.
GHS pictograms are for workplace and supply labels and have a red border with a black symbol on white. DOT transport labels and placards use colored backgrounds and class numbers and are required for shipping under hazardous materials rules. The two systems share symbols but serve different readers, so packages often carry both.
Yes. Some hazard categories, such as Category 4 flammable liquids, carry a signal word and hazard statement but no pictogram. Other products are not classified as hazardous and need no GHS label elements. An SDS may still be provided. A missing pictogram does not prove a product is harmless, so check Section 2 of the SDS.
The revision adopted by the regulator in the country where the product is supplied or used. In the US, that is the version in the current HCS, now aligned with Revision 7. Australia uses Revision 7 under WHS laws. Suppliers exporting to several countries often keep multiple label and SDS versions for each market.
Part of SafetyIQ's EHS glossary: plain-English definitions of workplace health and safety terms.
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