An international globally harmonised system for classification and labelling of chemicals (GHS) has been available since 2003. In Europe, the CLP (Classification, Labelling and Packaging) Regulation implements this system in the workplace and for consumers. The Regulation is being gradually applied and will eventually replace the pre-existing European system in 2015.
After explaining the use of labelling, this article aims to present the scope of the GHS, its impact in Europe and the current European classification and labelling systems of chemicals.
To alert users to the health and environmental hazards of chemicals, European Regulations call for the use of safety labels on packaging of these products. These labels also inform users of the precautions to take to safely handle, store and dispose of the chemicals.
Labelling of chemicals is based on their classification, which involves determining the hazard category to which the chemical belongs and assigning a codified regulatory phrase describing the type of hazard (hazard statement according to the CLP regulation, risk phrase in the pre-existing European regulations) (see chapter 'CLP regulation' below).
There are two types of chemicals according to the Regulations: substances and mixtures (or preparations, according to the pre-existing European regulations):
- Substance means a chemical element and its compounds in the natural state or obtained by any manufacturing process, e.g. acetone, ethanol, formaldehyde, silica, sodium hydroxide and chlorine.
- Mixtures or preparations are composed of two or more substances, e.g. solutions, detergents, inks and paints.
Note: In the pre-existing European system of classification and labelling of chemicals (see chapter 'Pre existing European system below), the term 'danger' was used instead of 'hazard'.
The Globally Harmonised System of Classification and Labelling of Chemicals (GHS) is a set of recommendations prepared at international level. Adopted by the United Nations Economic and Social Council, it is intended to harmonise existing systems and become the sole classification and labelling system at global level. The first version of the GHS was issued in 2003. A new revised version is published every two years. This 'Purple Book' can be downloaded from the United Nations Economic Commission for Europe (UNECE).
While covering workplaces, transport, consumers and emergency services, the GHS harmonises:
- the criteria for classification used to identify chemical hazards;
- hazard communication elements (including requirements for labelling and safety data sheets).
Twenty-nine hazard classes have been defined, and most of them have been divided into hazard categories. For example, the GHS divides the flammable liquids class into four categories. For each hazard class and category, the GHS defines the criteria for classification and the associated labelling elements: hazard pictogram, signal word, hazard statement and precautionary statements.
The safety data sheet described in the GHS is mainly based on the European model described in Directive 91/155/EEC (repealed and replaced by theREACH regulation). It has 16 sections.
The implementation plan of the World Summit on Sustainable Development, held in Johannesburg in 2002, encouraged all countries to put the GHS into application as soon as possible, with a final objective of 2008. However, the process is still ongoing and, according to the EU Commission "The implementation of the GHS in the EU in 2008 makes the EU a front-runner in its uptake". Information about the status of implementation is provided by the United Nations.
The building block approach defined by the GHS enables countries or organisations like the European Union that adopt this system to choose the building blocks they wish to apply. They can then use these building blocks to develop a regulatory approach. The GHS describes what can be considered as building blocks, i.e. hazard classes and hazard categories, and establishes rules for 'customising' a classification and labelling system so as to maintain consistency in the application of the GHS.
This section only describes the labelling systems used in the workplace and for consumers. The main differences between the pre-existing and current systems are explained. Regarding transport labelling, the European system is based on the United Nations Recommendations on the Transport of Dangerous Goods
Pre-existing European system
For several decades in Europe, the classification, labelling and packaging system of chemicals has been based on two Directives:
- Directive 67/548/EEC of 27th June 1967 concerning the classification, packaging and labelling of dangerous substances as modified (including later amendments)
- Directive 1999/45/EC of 31st May 1999 concerning the classification, packaging and labelling of dangerous preparations as modified (successor to earlier Directives).
These Directives and their subsequent amendments have been transposed into national law (e.g. two ministerial orders in France) for application in the different Member States of the European Union.
Classification according to the pre-existing system
The pre-existing system is based on the definition of 15 categories of danger, i.e. substances and preparations that are explosive, oxidising, extremely flammable, highly flammable, flammable, very toxic, toxic, harmful, corrosive, irritant, sensitising, carcinogenic, mutagenic, toxic for reproduction and dangerous for the environment.
Classification was generally characterised by a category of danger (which can be designated by an abbreviation) and a risk phrase.
Examples of classification: carcinogenic category 1; R45 (Carc. Cat. 1; R45); extremely flammable; R12 (F+; R12).
There is a list of substances (see below) for which the classification and labelling were set at European level (so-called harmonised classification and labelling) and must be applied in all Member States. This list is not an exhaustive list of dangerous substances. If no harmonised classification has been established, the manufacturer, importer or distributor is responsible for evaluating the dangers and determining the classification of the substance to be placed on the market. In this case, classification is based on criteria established in regulations and generally on experimental test results: flash point for determining the flammability of liquids, LD<sub50 (‘median’ lethal dose in experimental animals) for determining acute toxicity, etc.
For a preparation, classification is in principle based on physico-chemical test results. Concerning the hazards for human health and the environment, test results may in most cases be considered, but generally a calculation method integrating the classification and content of the hazardous substances in the preparation is used.
Labelling according to the pre-existing system
According to the pre-existing regulatory system, the labels applied on chemicals must include in particular the following:
- the danger symbols and indications of danger (see Figure 1) that indicate the most significant dangers posed by the chemical;
- the risk phrases:
Examples: R10: flammable; R36: irritating to eyes; R62: risk of impaired fertility;
- the safety phrases:
Examples: S45: In case of accident or if you feel unwell, seek medical advice immediately (show the label where possible); S53: Avoid exposure – obtain special instructions before use.
Member States requested the European Commission to prepare a proposal for a Regulation which would adopt the GHS criteria of the United Nations in all EU Member States. In the workplace and for consumers, the GHS recommendations will be progressively put into application by EC Regulation 1272/2008 of 16th December 2008, referred to as the CLP (Classification, Labelling and Packaging) Regulation. Many of the international recommendations were taken into consideration. The first adaptations to technical and scientific progress were made in 2009, 2011, 2012, June 2013 and August 2012.
The purpose of this Regulation is to harmonise the criteria for classification of substances and mixtures, and the rules on labelling and packaging for hazardous substances and mixtures. It also aims at establishing a classification and labelling inventory of substances. This Directive shall not apply to non-isolated intermediates, waste, medicines, cosmetics, food and feeding stuffs, and substances and mixtures that are either radioactive, or subjects to custom supervision, or used for scientific research and are non-marketed. This Regulation shall not apply to the transport of dangerous goods by air, sea, road, rail or inland waterways except for labelling of outer packaging, inner packaging and single packaging.
The current European Union CLP Regulation is directly applicable in all Members States and does not have to be transposed.
The most important modifications between the pre-existing European system and the current CLP Regulation include the following:
- change in vocabulary: 'hazard classes' replaces 'categories of danger', 'mixtures' replaces 'preparations';
- redefinition of hazards: whilst the pre-existing European system was based on 15 categories of danger, the CLP Regulation uses three hazard groups (physical hazards, health hazards, environmental hazards) and the 29 hazard classes described in the GHS:
- sixteen classes of physical hazards: explosives, flammables gases, flammable aerosols, oxidising 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, oxidising liquids, oxidising solids, organic peroxides, corrosive to metals;
- eleven classes of health hazards: acute toxicity, skin corrosion/irritation, serious eye damage/eye irritation, respiratory or skin sensitisation, germ cell mutagenicity , carcinogenicity, toxic to reproduction, specific target organ toxicity – single exposure, specific target organ toxicity – repeated exposure, aspiration hazard;
- two classes of environmental hazards: hazardous to the aquatic environment, hazardous to the ozone layer (referred to as 'additional hazard' in the CLP Regulation).
The hazard classes are assigned to hazard categories which describe the severity of the effect (e.g. health hazards are broken down from the highest category 1 to the lowest category 5; self-reactive substances are assigned to Type A being the most hazardous and Type F being the least hazardous) (that corresponds to the building blocks).
One the one hand the CLP includes some EU specific Hazard statements compared to the GHS (e.g. hazardous for the ozone layer), on the other hand the CLP applied the building block approach so that certain hazard categories that were not in the previous EU classification legislation have been left out (e.g. flammable liquid, category 4 in GHS is not part of the CLP).
- Changes in the criteria for classification: physical hazard classification is now based on tests described in international recommendations on the transport of dangerous goods, mixture classification criteria relative to health hazards are significantly different, changes have been made to classification thresholds, etc.
- Labelling changes: danger symbols and indications of danger have been replaced by hazard pictograms (Figure 2).
A signal word must generally be shown on the label. The words 'DANGER' (used for the most severe hazard categories) and 'WARNING' are used.
Risk phrases are replaced by hazard statements associated with an alphanumerical code consisting of the letter H and 3 digits (see Table 1 below).
- H290: 'May be corrosive to metals'
- H350: 'May cause cancer'
The wording of the precautionary statements ('safety phrases' in the pre-existing European system) has been modified as well as the associated codification: the alphanumerical code consists of the letter P and 3 digits (see Table 2 below).
- P235: 'Keep cool'
- P361: 'Remove/take off immediately all contaminated clothing'
Additional statements, such as supplemental hazard information or label elements, were in most cases reused from the pre-existing system and codified using 'EUH' + 3 digits.
- EUH066: 'Repeated exposure may cause skin dryness or cracking'.
- EUH204: 'Contains isocyanates. May produce an allergic reaction'.
Table 1: List of hazard statements, supplemental hazard information and supplemental label elements
Table 2: List of precautionary statements
All substances on the EU market on 1 December 2010 should have been notified to the European Chemicals Agency (ECHA) before the 3 January 2011. New substances should be notified within one month of their placement on the market to ECHA. This information as well as the data collected and registered under the REACH Regulation are used to supply a classification and labelling inventory. As of the end of 2014, ECHA had received 6 million notifications for more than 120,000 substances. Section V of the CLP Regulation sets out the provisions for the establishment of and notification to the inventory.
The procedure for harmonisation of classification and labelling of substances described in the CLP Regulation replaces the pre-existing European procedure.
The list of harmonised classification and labelling for hazardous substances, which was drawn up for the pre-existing system, is now included in Annex VI of the CLP Regulation Part 3 of this annex includes two tables:
- Table 3.1 includes the list of harmonised classifications and labellings based on the criteria of the CLP Regulation.
- Table 3.2 contains the same information as Table 3.1 but prepared according to the pre-existing system.
The annex was completed and modified by several adaptations to technical and scientific progress to the CLP Regulation.. When searching for a classification, these adaptations must first be consulted, followed by the CLP Regulation.
The following substances shall normally be subject to harmonised classification and labelling according to the CLP Regulation:
- carcinogenic substances;
- mutagenic substances;
- substances toxic for reproduction;
- respiratory sensitisers;
- active substances in biocidal or plant protection products;
- on a case-by-case basis, substances with other hazard classes than those referred above if justification can be provided demonstrating the need for such action.
A proposal for harmonised classification and labelling can be submitted to the European Chemicals Agency (ECHA) by Member State competent authorities, manufacturers, importers and downstream users.
Until 2017, two types of labels were on the European market; the pre-existing regulatory system and the system described in the CLP Regulation coexisted during this transition period. As of 1st December 2010, substance labelling must comply with the CLP Regulation. But, until 1st June 2015, the two systems of substance classification must have been mentioned on the safety data sheet.
Concerning mixtures, until 1st June 2015 classification and labelling had to comply with the pre-existing system, after which the CLP Regulation must have been applied. However, the CLP Regulation may have been put into application earlier on a voluntary basis. In such cases, the label should have complied with the CLP Regulation, but the safety data sheet had to continue to include both the mixture classification under the pre-existing system and the CLP classification.
Only substances and mixtures placed on the market before 1st December 2010 and 1st June 2015, respectively, could benefit from a re-labelling and re-packaging exemption for 2 years and could therefore continue to use labelling compliant with the pre-existing system until 1st December 2012 and 1st June 2017, respectively. However, Directives 67/548/EEC (on dangerous substances) and 1999/45/EC (on dangerous preparations) were totally repealed in 2015. All labeling must now therefore be compliant with the CLP Regulation.
In addition to replacing previous provisions on labelling, EU Directive 2014/27/EU  amended several OSH Council Directives in order to align them to the CLP Regulation. These directives include:
- Directive 92/58/EEC - safety and/or health signs
- Directive 92/85/EEC - pregnant workers
- Directive 94/33/EC - young workers
- Directive 98/24/EC - risks related to chemical agents at work
- Directive 2004/37/EC - carcinogens or mutagens at work
 UNECE – United Nations Economic Commission for Europe (undated), Information on the GHS and download of this 'Purple Book'. Retrieved 1 July 2015, from: 
 EU. Classification and Labelling (CLP/GHS) Available at: https://ec.europa.eu/growth/sectors/chemicals/classification-labelling_en (Accessed 30 May 2017)
 UNECE – United Nations Economic Commission for Europe, Information on United Nations (no date). GHS implementation. Retrieved 1 July 2015, from: 
 UNECE – United Nations Economic Commission for Europe, Information on United Nations (undated). Recommendations on the Transport of Dangerous Goods. Retrieved 20 January 2015, from: 
 European Council, Directive 67/548/EEC of 27 June 1967 on the approximation of laws, regulations and administrative provisions relating to the classification, packaging and labelling of dangerous substances, Official Journal 196. Available at: 
 European Parliament and European Council, Directive 1999/45/EC of 31 May 1999 concerning the approximation of the laws, regulations and administrative provisions of the Member States relating to the classification, packaging and labelling of dangerous preparations, OJ L 200, 30.7.1999. Available at:  (consolidated version).
 INRS, La fiche de données de sécurité, 2012. Available at: 
 European Parliament and European Council, Regulation (EC) No 1272/2008 of 16 December 2008 on classification, labelling and packaging of substances and mixtures, amending and repealing Directives 67/548/EEC and 1999/45/EC, and amending Regulation (EC) No 1907/2006, OJ L 353. Available at:  (including later amendments)
 EU-OSHA - European Agency for Safety and Health at Work (2015). Dangerous substances. CLP. Retrieved 1 July 2015, from: 
 ECHA - European Chemicals Agency (no date). C&L Inventory. Retrieved 1 July 2015, from: 
 ECHA – European Chemicals Agency, CLP pages. Retrieved 19 January 2015, from: 
 European Parliament and European Council, Directive 2014/27/EU of the of 26 February 2014 amending Council Directives 92/58/EEC, 92/85/EEC, 94/33/EC, 98/24/EC and Directive 2004/37/EC of the European Parliament and of the Council, in order to align them to Regulation (EC) No 1272/2008 on classification, labelling and packaging of substances and mixtures, OJL 65/1. Available at: 
BG RCI – Berufsgenossenschaft Rohstoffe und Chemische Industrie (no publishing date). GHS converter. Retrieved 1 July 2015, from: http://www.gischem.de/ghs/index.htm?client_locale=EN
EU-OSHA - European Agency for Safety and Health at Work (2015). Dangerous substances. CLP. Retrieved 1 July 2015, from: https://osha.europa.eu/en/themes/dangerous-substances/clp-classification-labelling-and-packaging-of-substances-and-mixtures
EU-OSHA - European Agency for Safety and Health at Work (2015). Napo. Napo's films. Napo in... Danger: chemicals! Retrieved 1 July 2015, from: http://www.napofilm.net/en/napos-films/multimedia-film-episodes-listing-view?set_language=es&filmid=napo-012-danger-chemicals
EU-OSHA - European Agency for Safety and Health at Work, DANGER: CHEMICALS! Do you know what these pictograms mean?, poster, 2012. Available at:https://osha.europa.eu/en/tools-and-publications/publications/promotional_material/clp-poster/view
EU-OSHA - European Agency for Safety and Health at WorkDanger: chemicals! The hazard pictograms explained, leaflet, 2012. Available at: https://osha.europa.eu/en/tools-and-publications/publications/promotional_material/clp-leaflet/view
EU-OSHA - European Agency for Safety and Health at Work, 'Dangerous substances and successful workplace communication', E-fact 75, 2013. Available at: https://osha.europa.eu/en/tools-and-publications/publications/e-facts/e-fact-75-dangerous-substances-and-successful-workplace-communication/view
European Commission, Chemicals at work – a new labelling system, 2013. Available at: http://ec.europa.eu/social/main.jsp?catId=738&langId=en&pubId=7634
HSE – British Health and Safety Executive (no publishing date). The CLP Regulation. Retrieved 1 July 2015, from: http://www.hse.gov.uk/chemical-classification/legal/clp-regulation.htm
INRS – Institut national de recherche et de sécurité (no date). Classification et étiquetage des produits chimique(Classification and labeling of chemicals). Retrieved 1 July 2015, from: http://www.inrs.fr/risques/classification-etiquetage-produits-chimiques/ce-qu-il-faut-retenir.html