GHS – Hazard Communication Overview

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 universally defined Hazard Classes based on specific criteria.

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.

Labels: Chemical manufacturers and importers are required to provide a label that includes a Signal Word, Pictogram(s), Hazard Statement(s), and Precautionary Statement(s) for each Hazard Category within a given Hazard Class.

Safety Data Sheets: Now have a standardized 16-section format.


  • GHS Health Hazard Classes (subdivided by Hazard Categories with associated Pictograms, Signal Word, and Hazard Statements):

GHS Health Hazards Table Image

GHS Physical Hazards Table Image