Labelling of chemicals

Introduction

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 was published in 2008 and has gradually been applied. The transition period with the pre-existing European system ended 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.

Definitions

To alert users to the health and environmental hazards of chemicals, the EU Regulation 1272/2008 on classification, labelling and packaging of substances and mixtures (CLP)^[1] 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) (see chapter 'CLP regulation' below).

There are two types of chemicals according to the Regulations: substances and mixtures:

• 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.

Globally harmonised system of classification and labelling of chemicals (GHS)

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)^[2].

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 the REACH regulation^[3]). 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. An overview of the status of implementation worldwide is available on the website of UNECE^[4]. The United Nations adopted in 2015 the Agenda 2030 for Sustainable Development^[5]. GHS implementation is key for achieving target 12.4 of Agenda 2030 relating to the sound management of chemicals by contributing to risk reduction, the strengthening knowledge and information sharing^[4]. 

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.

European systems of classification and labelling of chemicals

This section only describes the labelling systems used in the workplace and for consumers. The main differences between the pre-existing and current system are explained. Regarding transport labelling, the European system is based on the United Nations Recommendations on the Transport of Dangerous Goods^[6]

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^[7] 
• Directive 1999/45/EC of 31st May 1999 concerning the classification, packaging and labelling of dangerous preparations^[8]

These Directives and their subsequent amendments have been transposed into national law 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 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. 

For a preparation, classification is 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:

• the danger symbols and indications of danger of 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.

Figure 1: Danger symbols and indications of danger according to Directive 67/548/EEC

CLP Regulation

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. Regulation No 1272/2008 of the European Parliament and of the Council 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 1907/20061, referred to as the CLP Regulation^[1], came into force in 2008. Since then, the Regulation has undergone several amendments, mostly adaptations to technical and scientific progress.

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. The Regulation does 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. The Regulation also does 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 CLP Regulation is directly applicable in all Members States and does not have to be transposed.

Main changes

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 29 hazard classes. To these hazard classes, one has been added in 2019 and four in 2023 (see table 1). 

Table 1 – CLP Hazard groups and classes

Figure 2: CLP hazard pictograms according to EC Regulation 1272/2008

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).

On 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 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.

Examples:
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.

Examples:
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.

Examples:
EUH066: 'Repeated exposure may cause skin dryness or cracking'.
EUH204: 'Contains isocyanates. May produce an allergic reaction'.

Classification & Labelling inventory

The Classification and Labelling Inventory (C&L Inventory) contains classification and labelling information on notified and registered substances received from manufacturers and importers as well as the list of harmonised classifications and the names of harmonised substances translated in all EU languages^[11]. 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 the C&L Inventory. This information as well as the data collected and registered under the REACH Regulation are used to supply the C&L inventory. Section V of the CLP Regulation sets out the provisions for the establishment of and notification to the inventory.

The list of harmonised classification and labelling for hazardous substances is included in Annex VI of the CLP Regulation (table 3.1).

The following substances are subject to harmonised classification and labelling according to the CLP Regulation^[12]:

• carcinogenic substances;
• mutagenic substances;
• substances toxic for reproduction;
• respiratory sensitisers;
• 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.

Occupational safety and health (OSH) legislation

Legislation on OSH is aligned with the CLP Regulation and uses the CLP classification to stipulate obligations for protecting the safety and health of workers. Examples include:

• Directive 92/58/EEC - safety and/or health signs (annex III Containers and pipes used at work for chemical substances or mixtures)^[13]
• Directive 92/85/EEC - pregnant workers (specific risk of exposure: substances and mixtures classified under CLP as mutagens, carcinogens, reprotoxic, specific target organ toxicity after single exposure – annex I )^[14];
• Directive 94/33/EC - young workers (specific risk of exposure: substances and mixtures classified under CLP as acute toxic, skin corrosives, etc. – annex)^[15]
• Directive 98/24/EC - risks related to chemical agents at work (part of the definition of ‘chemical agent’ – art. 2)^[16]
• Directive 2004/37/EC – carcinogens, mutagens or reprotoxic substances at work (definitions of carcinogens, mutagens and reprotoxic substances – art. 2)^[17]

Information for emergencies on mixtures

In 2017 an amendment was made to the CLP Regulation to improve the information requirements with regard to emergency health response^[18]. Companies placing hazardous mixtures on the market have to provide this information in a standardised format to the relevant national bodies. These relevant national bodies make this information available to poison centres so that they can give advice to the citizens or medical personnel in the event of an emergency. The obligations apply since 1 January 2021 with some transitional periods until 1 January 2025.

One of the information requirements is the so-called unique formula identifier (UFI). The UFI is a 16-character alphanumeric code that manufacturers print on the label. The code establishes a direct link between the information provided through the notification on a mixture and the corresponding product placed on the market. This allows poison control centres to quickly determine appropriate emergency measures in case of an incident. ECHA has set up a website to help companies, national bodies and poison centres with the emergency response requirements by providing the tools, guidance and support^[19].