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, with Category 1 as the most severe.
- For example, the Hazard Class “Serious Eye Damage/Eye Irritation” is divided into three Hazard Categories:
- Category 1: Irreversible Effects on the Eye. (“Danger; Causes serious eye damage”).
- Category 2A: Eye Irritant. (‘Warning; Causes serious eye irritation”). It may take up to 21 days for eye to fully heal.
- Category 2B: Mild Eye Irritant. (“Warning; Causes eye irritation”). It may take up to 7 days for the eye to fully heal.
- 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):