The Hazard Communication Standard (HCS) is now aligned with the Globally Harmonized System of Classification and Labeling of Chemicals (GHS).
- Hazard Classes. Chemicals (and chemical mixtures) are grouped into GHS-defined Hazard Classes based on specific criteria; i.e., flammable, carcinogen.
- Hazard Categories. Each Hazard Class is subdivided into Hazard Categories.
- These Categories are ranked based on hazard severity.
- For example, the Hazard Class “Flammable Liquids” is divided into four Hazard Categories, with Category 1 (“Danger; Extremely flammable liquid and vapor”) being the most severe, and Category 4 (“Warning; combustible liquid”) being the least severe.
- GHS Health Hazard Classes (subdivided by Hazard Categories with associated Pictograms, Signal Word, and Hazard Statements):
- GHS Physical Hazard Classes (subdivided by Hazard Categories with associated Pictograms, Signal Word, and Hazard Statements):