The Globally Harmonized System of Classification and Labelling of Chemicals (GHS) is a United Nations system that standardizes how chemical hazards are classified and communicated worldwide.
It was developed to replace the many different national labeling and classification systems that previously existed. This improves protection of human health and the environment, reduces the need for repeated testing, and makes international trade in chemicals safer and more efficient.
The first edition (“Purple Book”) was published in 2003. It is updated every two years. The current edition is GHS Rev. 11 (2025)
