GHS (Globally Harmonized System of Classification and Labeling of Chemicals) is a system introduced by the United Nations that defines the classification of hazards of chemical products and communication of health and safety information on labels and safety data sheets (SDS). Numerous countries have regulatory systems on chemicals. On an international market, the differences in the content may cause inconsistency of protection due to the widespread of use of chemical substances and mixtures.

Qu’est-ce que le SGH ?

The 2 main objectives of GHS

Classification of hazards – Consists of the identification of all relevant information of the hazard(s) of a pure substance or a mixture (physical hazards, health hazards, environmental hazards etc.)

Hazard Communication – After a substance or mixture has been classified, the hazard must be communicated through the main tools: labeling and Safety Data Sheets (SDSs).


The GHS was created at the United Nations Conference on Environment and Development (UNCED) in Rio 1992. It was designed by the United Nations to replace all the differences in systems between countries.

Many countries have different approaches to hazard classification and labeling of the same substances. As a consequence, there are multiple standards and regulations for the same hazard which is not ideal due to the continuous increase in international trade of chemicals. The GHS has the aim of harmonizing classification of hazards and labeling standards on an international level as a solution.

International Labour Organization (ILO) together with the Convention and Recommendation on Safety in the Use of Chemical at Work developed the tasks to achieve harmonization on a global level. GHS is now also the basis for international and national transport regulations for dangerous goods.


SDS (Safety Data Sheet) - Provides information about hazards and safety precautions for use of chemical(s) in a workplace.

H Statement – GHS standardized hazard statements giving information about the hazards of chemical substances and mixtures.

P Statement – GHS standardized precautionary statements giving advice on the correct handling of chemical substances and mixtures.

Pictogram – GHS symbols used for labeling of containers, workplace hazard symbols and transport of dangerous goods. Some categories do not have symbols associated with them. See more

Class - The term used to describe the different types of hazards. E.g. Explosives is an example of a class in the physical hazard group.

Categories - Category is used to describe the sub-sections of classes.

Signal Word – The word Danger or Warning are signals used to inform the level of hazard of the chemical substance or mixture on both the label and the SDS. The classification system gives the appropriate signal word to use. If substance is in category 1, the signal word to use is Danger whereas with less serious substances in Category 2, the signal word Warning will be used. Not all categories uses signal words.

Product identifier (ingredient disclosure): Name or number used for a hazardous product on a label or in the SDS.

Supplier identification: The name, address and telephone number provided on the label.

Implementation schedule

There is no exact international implementation schedule for the GHS. Countries will implement GHS at different times according to their local circumstances.

GHS around the World

 canadian flag

In Canada, WHMIS (Workplace Hazardous Material Information System) communicates national hazard standards. Canada’s WHMIS is now aligned with GHS. The WHMIS 2015 legislation is in force since February 11, 2015 however there’s a transition period to provide Canadian suppliers, employers and employees to adjust to the new requirements.

In the US, HAZCOM (Hazard Communication) chemical standards are also being aligned with the GHS. According to OSHA "this update to the Hazard Communication Standard (HCS) will provide a common and coherent approach to classifying chemicals and communicating hazard information on labels and safety data sheets".

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 eu flag

In the EU, CLP (Classification, Labeling and Packaging) is also aligned with the GHS to facilitate international trade and to promote regulatory efficiency. The CLP legislation complements the REACH Regulation (Registration, Evaluation, Authorisation and Restriction of Chemicals) of chemicals.

Differences in hazard classification

The main difference between those systems is due to the building block approach that is chosen. Indeed, in order to classify the hazards classes and categories related to a substance, building blocks are used.

According to the different geographical areas, some of the building blocks of the GHS are implemented or not. E.g. Aerosol, Cat. 3 is a building block that is implemented in the European Union but not in the US nor in Canada. Flammable liquids, Cat. 4 is a building block that is implemented in the US and in Canada but not in the EU.

The table below shows the differences between European, Canadian, American and Chinese implementation of the GHS for some of the building blocks.

   table building block  

Another difference is that OSHA Hazard Communication Standard environmental hazards are not required whereas under Safety Data Sheet for Europe exposure scenarios are required if available.

Differences in SDS mandatory sections

There are also major differences in the Safety Data Sheets between different systems. For example, all 16 sections of SDS under CLP are mandatory whereas section 12 & 15 can be omitted under HazCom and WHMIS formats.

Differences in labeling

The outer container of a kit (containing at least two different hazardous products) must be labeled in SDS under WMHIS. However for Safety format sheet in the USA, only the inner containers are required to be labeled. The outer container of a kit does not need to be labeled.

Implementation in various Countries and transitional periods

One notable difference between the systems in various countries is the implementation and transitional periods given in the country of the substances and mixtures.

EU (CLP) - GHS adopted into EU Classification, Labeling and Packaging (CLP) regulations which were in force as of 20th January 2009. The deadline for substance classification was the 1st of December 2010, whereas deadline for implementation of mixtures is the 1st of June 2015.

USA (HazCom) - Publication of final rule on the implementation of GHS on the 26th of May 2012.

  • 1st December 2013 – Workers to be trained on new label elements and SDS formats
  • 1st June 2015 – Product manufactures to comply with all modified standards and provisions
  • 1st December 2015 - ¨Product distributors to comply with new system

Canada (WHMIS) – In December 2011, Canada has committed to the implementation of the Globally Harmonized System (GHS) of Classification and Labeling of Chemicals for workplace chemicals in Canada by the 1st of June 2015.

3 major hazards

There are 3 major elements of hazard classification within the GHS system.

Physical Hazards:

  • Explosives
  • Flammable gases
  • Aerosols
  • Oxidizing gases
  • Gases under pressure
  • Flammable liquids
  • Flammable solids
  • Self-reactive substances and mixtures
  • Pyrophoric liquids
  • Pyrophoric solids
  • Self-heating substances and mixtures
  • Substances and mixtures which, in contact with water, emit flammable gases
  • Oxidizing liquids
  • Oxidizing solids
  • Organic peroxides
  • Corrosive to metals
human hazards

Health Hazards:

  • Acute toxicity
  • Skin corrosion/irritation
  • Serious eye damage/eye irritation
  • Respiratory or skin sensitization
  • Germ cell mutagenicity
  • Carcinogenicity
  • Reproductive toxicity
  • Specific target organ toxicity - single exposure
  • Specific target organ toxicity - repeated exposure
  • Aspiration hazard
health hazards

Environmental Hazards:

  • Hazardous to the aquatic environment (acute and chronic)
  • Hazardous to the ozone layer
environmental hazards

Want to learn more on GHS?

EcoMundo experts on GHS are at your service. Please feel free to send us an email at [email protected] if you need any additional information!

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