By Little Pro on 1 Jan 2015. Updated on 14 March 2018
The Globally Harmonized System of Classification and Labelling of Chemicals (GHS) is a system developed by the United Nations for standardizing and harmonizing the classification and labelling of chemicals globally. More specifically, the UN GHS Document (known as UN GHS Purple Book):
The UN GHS purple book is updated frequently and the latest version was the 7th revised edition released in 2017.
As a voluntary international system, the GHS is not legally binding in any country. Therefore, countries adopting GHS have to issue their own regulations or standards to implement GHS criteria and provisions. Two examples are:
Compared to pre-GHS hazard communication, GHS offers better protection to workers and users and facilitates international chemical trade.
In pre-GHS era, users may see different label warnings or safety data sheet information for the same chemical, which can cause confusion. In addition to that, most of countries have their own hazard classification and labelling regulations in pre-GHS era. Those regulations vary significantly and compliance with them is very costly and time-consuming.
The GHS covers all hazardous chemicals, i.e., chemicals meeting the criteria for a hazard class in the GHS. Sectors that may adopt GHS include:
Some countries have adopted GHS in all 4 sectors while other countries have only adopted GHS in 1 or 2 sectors. To check if your products require GHS labelling or Safety Data Sheets, you need to check whether your country has adopted GHS or not and which sector is applicable (if yes).
Pharmaceuticals, food additives, cosmetics and pesticide residues in food are not covered by the UN GHS (referring to chapter 1.1 of the UN GHS) at the point of consumption, but will be covered where workers may be exposed (workplaces), and in transport. Articles and foods are also usually out the scope of GHS.
GHS describes the nature and severity of a chemical hazard by hazard class and hazard category. GHS also assigns standard pictograms representing different types of hazards.
There are 29 hazard classes in the latest version of UN GHS ( UN GHS Rev. 7). A chemical meeting the criteria for any hazard class below will be regarded as a hazardous chemical.
|Physical Hazards(17 classes)
|Health Hazards(10 classes)
|Environmental Hazards(2 classes)
It shall be noted that the GHS allows individual countries or regions to choose which hazard classes or hazard categories to implement to meet their domestic needs. For example, EU has not adopted flammable liquids category 4. The United States has not adopted Hazardous to the Ozone Layer yet. This is often called GHS Building Blocks approach.
The picture below shows the type of chemical hazards each GHS pictogram represents. By clicking the picture below, you can download GHS pictograms and make your own GHS posters. The document is editable.
GHS classification is a process to determine the hazard class and category of a chemical (substance or mixture) in accordance with GHS hazard classification criteria.
The picture below is an example of GHS classification criteria for flammable liquids. A liquid with a flash point between 23 and 60 Celsius degrees will be classified as flammable liquid category 3. A liquid with a flash point above 93 Celsius degrees does not meet GHS classification criteria and will not be regarded as a hazardous chemical.
Download GHS Classification Criteria
Once a chemical has been classified according to GHS classification criteria, you can easily find assigned signal word, pictogram, hazard statements and precautionary statements that need to be included on labels and in SDSs.
For example, a liquid with a flash point between 23 and 60 Celsius degrees will be classified as flammable liquid category 3. By checking the page 316 of above document, you can easily find out the core labelling elements for this liquid:
Classification is very important but not easy. For substances, you need to have test data to carry out classification. Luckily you do not need to test every substance. Many countries or regions have published compulsory or advisory GHS classification lists for pure substances. You can directly refer to those classifications for your substances without doing the tests.
The most well-known GHS classification list is the annex VI of EU CLP regulation. It includes compulsory GHS classifications for thousands of substances.
The core elements of a GHS label include:
An example of a GHS label for a chemical can be found below:
Please be noted that:
Safety Data Sheet (SDS), also called as Material Safety Data Sheet (MSDS) in pre-GHS era, is a very important document to inform its audience of the hazards of a substance or mixture and provide advice on safety precautions.
An SDS should be prepared and provided for a substance or mixture meeting classification criteria for a hazard class or for a mixture containing an ingredient meeting criteria for carcinogenic, toxic to reproduction or specific target organ toxicity exceeding the cut-off value limits given in the following table.
GHS has harmonized the format and content of Safety Data Sheets. There are 16 sections in standard GHS SDSs (as shown below). GHS has also set the minimum info required for each section.
Please be noted that:
Many countries/regions have adopted GHS such as the United States, EU, China and Japan. By clicking the links below, you can find detailed info about how GHS is adopted in each country/region.