Hazard Classification and Communication

Hazard Classification: The process of evaluating scientific data to determine whether a chemical is hazardous and establish the severity level of the hazardous effect, identifying the associated hazard class and category.
Classifications vs. Categories:
- Hazard Classifications: Defined by the nature of a physical or health hazard, such as flammable solid, carcinogen, and acute toxicity.
- Hazard Categories: Divisions of criteria within each classification that compare hazard severity strictly within that specific class (e.g., acute toxicity and flammable liquids each include four hazard categories numbered one through four).
- Hierarchy Specificity: Category rankings apply only to their own classification; a category two in acute toxicity is not necessarily less toxic than a category one in a different classification.
Implementation: Provides the basis for information on SDSs, labels, and worker training.
Responsible Parties: Chemical manufacturers and importers must perform hazard classifications. Under the Hazard Communication Standard (HCS), an employer is considered a chemical manufacturer if they manufacture, process, formulate, blend, mix, repackage, or otherwise change the composition of a hazardous chemical.

Classification Scope: Hazard classification does not involve an estimation of risk.
Hazard: According to the globally harmonized system, an inherent property of a substance capable of causing an adverse effect.
Risk: The probability that an adverse effect will occur with specific exposure conditions.