The Globally Harmonized System

The Globally Harmonized System for Classification and Labeling, or GHS for short, is an international system used in many countries for determining the hazards of chemicals and to warn the users of chemicals about those hazards through labels and data sheets. In 2012 the US Occupational Safety and Health Administration (OSHA) revised its Hazard Communication Standard to adopt GHS and incorporate its label and information system.

Developing GHS

Over time different countries have developed different systems for chemical labels and data sheets. Parts of these systems conflict with each other. Countries also did not agree on the requirements for classifying chemicals as, for example, a carcinogen or a reproductive hazard. So a chemical could be listed as a reproductive hazard in one country and not in another.

These differences became problematic as more globalization occurred and chemicals were shipped from one country to another. Labels and data sheets from one country couldn’t necessarily be used in another. Workers around the world got conflicting, misleading, or no information.

In 1992 efforts began to create one uniform system to be used worldwide. Representatives from government, industry, labor unions, and international bodies participated to develop the classification system for health and environmental hazards and the system for hazard communication. Meetings are still held periodically to discuss adding hazard classifications and making other changes.

GHS in the United States

OSHA adopted GHS as a revision to its Hazard Communication Standard in 2012. This move was widely supported by both industry and labor. There is a transition period to implement GHS gradually between 2012 and June 2016.

The old Hazard Communication standard allowed chemical manufacturers and importers to convey hazard information on labels and material safety data sheets in any format they chose. The revised standard uses GHS hazard phrases and has a single set of criteria for classifying chemicals according to their health and physical hazards. It also specifies elements for communicating hazards through labels and safety data sheets.

GHS changes to the Hazard Communication Standard

There are four major changes to the Hazard Communication standard:

  1. Hazard classification - Chemical manufacturers and importers are still required to determine the hazards of the chemicals they produce or import. Under the revision, health and physical hazard classification determinations are now made using standard specific criteria. Not all health hazards are covered under GHS including chemicals that are toxic to the brain and nervous system.
  2. Labels - Chemical manufacturers and importers are now required to provide a label that includes a signal word, pictogram, hazard statement, and precautionary statement for each hazard class and category.
  3. Safety Data Sheets (SDS) - These replaced material safety data sheets (MSDS) and now have a format with 16 specific sections to ensure consistency in presenting important hazard and protection information.
  4. Information and training - The revision requires employers to provide workers with training on the new label elements and safety data sheet format in addition to the current Hazard Communication Standard training requirements by December 1, 2013.

Benefits for Workers

The development of GHS was a step forward for workers around the world towards the right to know about the chemicals and hazards they work with. Some countries, but not all, have adopted GHS.

The implementation of GHS in the United States will keep all of the original protections for workers under the Hazard Communication Standard, plus it will strengthen some of them. Information on labels and safety data sheets are now more uniform and easier to understand because of the standard format. The hazard warnings are also standardized and don't contain incomprehensible scientific language. For the first time, labels and data sheets will contain pictograms – symbols showing the hazard. These are especially important for workers who do not read well or who do not speak English.

This material is adapted from a factsheet by the United Steelworkers Health, Safety & Environment Department ( More information on GHS can also be found on OSHA’s website (