GHS: The Globally Harmonized System of Classification and Labelling
What is GHS?
The Globally Harmonized System of Classification and Labelling of Chemicals (GHS) is an internationally agreed-upon system created by the United Nations. It was developed to replace the various classification and labelling standards used in different countries by using consistent criteria for classification and labelling on a global level.
Purpose of GHS
The key aims of GHS are to:
- Enhance protection of human health and the environment by providing an internationally comprehensible system for hazard communication.
- Provide a framework for countries that do not yet have their own classification and labelling system.
- Reduce the need for testing and evaluation of chemicals by promoting international acceptance of hazard data.
- Facilitate international trade in chemicals whose hazards have been properly assessed on an international basis.
GHS Pictograms
GHS uses nine standardised hazard pictograms to communicate specific types of hazards. Each pictogram is a red-bordered diamond shape containing a black symbol on a white background:
Physical Hazard Pictograms
- GHS01 - Exploding Bomb: Explosives, self-reactive substances, organic peroxides
- GHS02 - Flame: Flammable substances (gases, aerosols, liquids, solids)
- GHS03 - Flame Over Circle: Oxidizing substances
- GHS04 - Gas Cylinder: Gases under pressure
- GHS05 - Corrosion: Corrosive to metals, causes skin burns and eye damage
Health Hazard Pictograms
- GHS06 - Skull and Crossbones: Acute toxicity (fatal or toxic)
- GHS07 - Exclamation Mark: Irritant, sensitizer, narcotic effects, less severe hazards
- GHS08 - Health Hazard: Carcinogenicity, mutagenicity, reproductive toxicity, organ toxicity
Environmental Hazard Pictograms
- GHS09 - Environment: Hazardous to the aquatic environment
Hazard Statements (H-Statements)
Hazard statements are standardised phrases that describe the nature and severity of a chemical hazard. They are identified by an alphanumeric code starting with "H" followed by three digits:
- H200 series: Physical hazards (e.g., H220 - Extremely flammable gas)
- H300 series: Health hazards (e.g., H301 - Toxic if swallowed)
- H400 series: Environmental hazards (e.g., H410 - Very toxic to aquatic life with long lasting effects)
Precautionary Statements (P-Statements)
Precautionary statements provide advice on how to minimise or prevent adverse effects resulting from exposure to a hazardous chemical, or from improper storage or handling. They are identified by codes starting with "P" followed by three digits:
- P100 series: General precautionary statements
- P200 series: Prevention
- P300 series: Response
- P400 series: Storage
- P500 series: Disposal
Signal Words
GHS uses two signal words to indicate the relative level of severity of a hazard:
- Danger: Used for more severe hazard categories
- Warning: Used for less severe hazard categories
Only one signal word is used on a label, and "Danger" takes precedence over "Warning" when multiple hazards are present.
Safety Data Sheets (SDS)
GHS defines a standardised 16-section Safety Data Sheet (SDS) format that provides comprehensive information about a chemical substance or mixture. The 16 sections are:
- Identification
- Hazard(s) identification
- Composition/information on ingredients
- First-aid measures
- Fire-fighting measures
- Accidental release measures
- Handling and storage
- Exposure controls/personal protection
- Physical and chemical properties
- Stability and reactivity
- Toxicological information
- Ecological information
- Disposal considerations
- Transport information
- Regulatory information
- Other information
GHS Implementation Worldwide
GHS has been implemented by many countries around the world, though the extent and timing of implementation varies. In the European Union, GHS is implemented through the CLP Regulation. Other major implementations include:
- United States: Implemented through OSHA's Hazard Communication Standard (HCS 2012)
- Japan: Implemented through the Industrial Safety and Health Act
- China: Implemented through national standards (GB standards)
- South Korea: Implemented through the Chemical Control Act
- Australia: Implemented through the Work Health and Safety Regulations
It is important to note that while GHS provides a harmonised framework, countries may implement different building blocks or apply different classification thresholds, so some differences may remain between jurisdictions.