The GHS addresses classification of chemicals by types of hazard and proposes harmonized hazard communication elements, including labels and safety data sheets. It aims at ensuring that information on physical hazards and toxicity from chemicals be available in order to enhance the protection of human health and the environment during the handling, transport and use of these chemicals.

The GHS also provides a basis for harmonization of rules and regulations on chemicals at national, regional and worldwide level.

The first edition of the GHS, which was intended to serve as the initial basis for the global implementation of the system, was adopted in December 2002 and published in 2003.

Since then, the GHS has been updated, revised and improved every two years as needs arise and experience is gained in its implementation:

GHS Rev.1 (2005): includes, inter alia, various revised provisions concerning classification and labelling, new provisions for aspiration hazards and new guidance on the use of precautionary statements and pictograms and on the preparation of safety data sheets

GHS Rev.2 (2007): includes, inter alia, new and revised provisions concerning the classification and labelling of explosives; respiratory and skin sensitizers; toxic by inhalation gases and gas mixtures; additional guidance on the interpretation of the building block approach and on the evaluation of the carcinogenic potential of chemicals; and the codification of hazard and precautionary statements

GHS Rev.3 (2009): includes, inter alia, new provisions for the allocation of hazard statements and for the labelling of small packagings; two new sub-categories for respiratory and skin sensitization; the revision of the classification criteria for long-term hazards (chronic toxicity) to the aquatic environment; and a new hazard class for substances and mixtures hazardous to the ozone layer

GHS Rev.4 (2011):  includes, inter alia, new hazard categories for chemically unstable gases and non-flammable aerosols; further rationalization of precautionary statements and further clarification of some of the criteria to avoid differences in their interpretation

GHS Rev.5 (2013):  includes, inter alia, a new test method for oxidizing solids, miscellaneous provisions intended to further clarify the criteria for some hazard classes (skin corrosion/irritation, severe eye damage/irritation, and aerosols) and to complement the information to be included in the Safety Data Sheet; revised and simplified classification and labelling summary tables; a new codification system for hazard pictograms, and revised and further rationalized precautionary statements.

GHS Rev.6 (2015): includes, inter alia, a new hazard class for desensitized explosives and a new hazard category for pyrophoric gases; miscellaneous provisions intended to clarify the criteria for some hazard classes (explosives, specific target organ toxicity following single exposure, aspiration hazard and hazardous to the aquatic environment); additional information to be included in the Safety Data Sheets (section 9); revised and further rationalized precautionary statements and a new example in Annex 7 addressing labelling of small packagings.

GHS Rev.7 (2017): includes, inter alia, revised criteria for categorisation of flammable gases within Category 1; miscellaneous amendments intended to clarify the definitions of some health hazard classes; additional guidance to extend the coverage of section 14 of the Safety Data Sheets to all bulk cargoes transported under instruments of the International Maritime Organisation (IMO), regardless of their physical state; revised and further rationalized precautionary statements in Annex 3; and a new example in Annex 7 addressing labelling of small packagings with fold-out labels.