UN GHS refers to the Globally Harmonized System of Classification and Labelling of Chemicals (purple book). It is an international system created by United Nations Committee of Experts on GHS, International Labor Organization (ILO) and the Organization for Economic Co-operation and Development (OECD) to address the classification of chemicals by types of hazards and harmonize hazard communication elements, including labels and safety data sheets. It aims at providing a basis

Various international transport of dangerous goods regulations have requirements for an emergency telephone number to be available at all times for all shipments, there are a number of specific requirements for certain types of goods. There are also many national requirements and transport operator rules that may require emergency contact details to be provided. Many countries have now adopted the GHS (Globally Harmonized System of Classification and Labelling of Chemicals)