All over the world there are different laws on how to identify the hazardous properties of chemicals (called ‘classification’) and how information about these hazards is then passed to users (through labels, and safety data sheets for workers).

This can be confusing because the same chemical can have different hazard descriptions in different countries. For example, a chemical could be labelled as ‘toxic’ in one country, but not in another.

The UN brought together experts from different countries to create the Globally Harmonized System of Classification and Labelling of Chemicals (GHS).

The aim of the GHS is to have, worldwide, the same:

• criteria for classifying chemicals according to their health, environmental and physical hazards; and
• hazard communication requirements for labelling and safety data sheets.

The UN GHS is not a formal treaty, but instead is a non-legally binding international agreement. Therefore countries (or trading blocks) must create local or national legislation to implement the GHS.

• Implications and guidance