The introduction of the Global Harmonised System of Classification and Labelling of Chemicals (GHS) back in 2002, was the first step towards a global approach to understanding and managing the health and safety risks of chemicals and their use.
Although chemicals have helped improve many aspects of our lives, they also continue to pose a risk. The International Labour Organization (ILO) demonstrated that occupational exposures to such hazardous materials is responsible for no fewer than 1,000,000 deaths each year, globally. These fatalities do not include the harm to the wider community through exposure, such as accidental releases or inappropriate disposal practices.
The 1984 Bhopal gas tragedy, where an estimated 574,000 individuals were exposed to noxious clouds of Methyl Isocyanate (MIC), a highly toxic substance used in the production of carbamate pesticides, is an example of this.
The GHS provide guidelines around the safe use, handling and storage of hazardous material for everyone along the value chain, including manufacturers, importers, suppliers and the end users of the products.
It means manufacturers and suppliers are required to evaluate the health and safety risks associated with a substance before introducing it to market, and then effectively communicate and label that information to and for anyone coming into contact with the chemical.
This is intended to ensure that anyone handling the chemical can understand, evaluate and manage the risks of that substance through its GHS classification and label.
End-users of chemicals are also responsible in that they are obliged to familiarise themselves with the chemical labelling and requirements, understand the nature and severity of the hazard associated with the substance, and then apply the compliant safety control measures for its safe handling, storage and disposal.
GHS Assessment criteria
The GHS is comprised of a ‘harmonised’ set of assessment criteria and communication elements which are used to determine and convey the nature and severity of the hazard(s) associated with a particular substance or mixture.
Each substance or mixture is evaluated using a ‘tiered approach’, and assigned a Hazard Classification according to the criteria it aligns to.
Each GHS Hazard Classification reflects the specific nature of the risk posed by the material i.e. Health Hazard, Physical Hazard, or Environmental Hazard, with further ‘Hazard Categories’ for each that identifies the severity of the respective hazard.
In total, there are 29 individual Hazard Classifications as defined in the latest version of the GHS (6th Revised Edition). Of these, 17 are Physical Hazards, ten are Health Hazards, and two are Environmental Hazards.
Communicating the hazards
Each Hazard Classification and / or Hazard Category comes with a standardised set of communication elements to identify and convey the risks of the substance in the Safety Data Sheet (SDS), along with the practical guidance for its safe handling, storage and disposal.
These elements are might include Signal Word, Hazard Code, Hazard Statement, illustrative Pictogram, and number of Precautionary Statements.
By design, the GHS affords individual nations or regions the opportunity to ‘pick and choose’ which hazard classes or categories they wish to implement for their respective domestic needs. This is colloquially known as the GHS Building Block approach. This means the applicability of the Hazard Classifications and / or Hazard Categories is hugely dependent upon the GHS Building Blocks adopted by each jurisdiction.