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, an important factor also for trade facilitation. This fourth revised edition of the GHS contains various new or revised provisions concerning, 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.--Publisher's description.