The United Nations (UN) estimates that there are over 100,000 chemicals present on the global market, some 20,000 of which are considered to be dangerous. Given this extensive use of dangerous chemicals on the global market, a global approach to their safe use, transport and disposal is imperative. The protection of human health and the environment has been a primary focus of the UN for many years, specifically addressed in Agenda 21, which originated at the Rio Earth Summit in 1992. Among other objectives, Agenda 21 sets a defined programme for the environmentally sound management of toxic chemicals worldwide, which has six focus areas including the harmonisation of classification and labelling of chemicals and the establishment of risk reduction programmes. In practice, the technical implementation of this Agenda 21 has been primarily driven by the United Nations Economic Commission for Europe (UNECE), based in Geneva, which includes 56 member states in Europe, North America and Asia, with the other four regional commissions of the UN following more slowly.

Harmonisation of classification and labelling

Following the Rio Summit, work began on the UN Globally Harmonised System of Classification and Labelling of Chemicals (GHS), establishing a common and coherent basis for chemical hazard classification and communication tools, such as labelling and safety data sheets relevant for transportation, consumers, worker and environmental protection. UNECE published the first edition of the GHS Purple Book in 2003 and it is amended every two years based on developments in scientific knowledge. While GHS provides a universal framework for all countries to follow, it is not compulsory, but is intended to be implemented by individual countries through their own legal instruments, recommendations, codes and guidelines, etc. The implementation of GHS in the European Union (EU) follows through the Classification, Labelling and Packaging (CLP) Regulation (i.e. Regulation (EC) No. 1272/2008). The CLP Regulation in the EU differs from the UN’s GHS in that it is interlinked with the EU’s Regulation (EC) No. 1907/2006 on Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH). The REACH Regulation was the mandate by which the European Chemicals Agency (ECHA) was set up, and this organisation now forms the driving force behind implementation of the EU’s chemicals legislation. Chemical suppliers in the EU provide ECHA with information on hazards associated with their products. In some cases, ECHA can define a harmonised classification for a particular substance, although a harmonised classification may be often limited to certain hazard categories only. The CLP regulation is regularly updated to include the new and updated harmonised classifications, as they are developed, but there is a long way to go on developing these harmonised classifications. For example, the harmonised classification for Jet Fuel in ECHA assigns the substance with the hazard: ‘May be fatal if swallowed and enters the airways’ (H304). But additional classification provided by suppliers to ECHA for this substance also includes the hazards of toxic to aquatic life with long-lasting effects; a flammable liquid and vapour; a skin irritant and a cause of drowsiness or dizziness. This is where it can get tricky to determine the most appropriate hazard classification, as the inclusion of all or any of these additional hazards is open to interpretation. This requires significant attention to detail and expert judgement based on the capability of the substance or mixture in question to meet the criteria for classification of that hazard category in GHS.

The importance of GHS

There are a number of reasons which make understanding of, and compliance to GHS, such an important part of global chemical trading and chemical safety, including: 1. Need to comply with GHS requirements on a global scale GHS is increasingly becoming a truly global standard; it has already been implemented or is in the process of being implemented by 72 countries. For example, in China, GHS is implemented by several compulsory national and recommended national standards. Exporters wishing to trade with China and indigenous Chinese chemical companies must adopt these standards to classify label and package chemicals and prepare appropriate Safety Data Sheets. GHS has also been adopted in the US as the Occupational Safety and Health Administration’s (OSHA) Hazard Communication Standard. In Canada, the government have made necessary changes to the Hazardous Products Act and recently introduced the Hazardous Product Regulations (2015). In Australia, the Model Work Health and Safety laws have implemented GHS there. 2. Requirement to provide safety data sheets to downstream users In the EU, the REACH Regulation requires the supplier of a substance or a mixture to make available a safety data sheet (SDS) for downstream users upon request, where the substance in question meets the criteria for classification as hazardous in accordance with the CLP Regulation. There are a number of specific exemptions to this requirement, however, such as food products for the final consumer. Globally, GHS has a general requirement that an SDS should be produced for all substances and mixtures, which meet the harmonised criteria for physical, health or environmental hazards and for all mixtures, which contain ingredients that meet the criteria for carcinogenic, toxic to reproduction or target organ toxicity above certain defined concentrations. Therefore, it is particularly important for suppliers of chemicals, which possess hazardous properties, to classify these mixtures correctly in order to identify, which hazards remain applicable to the mixture itself. This will determine the necessity of an SDS for these mixtures. 3. Requirement to provide adequate occupational safety information Under the UK’s and Ireland’s ‘common law’ system, a general duty of care emanates from the Health and Safety at Work legislation, which obliges suppliers to provide adequate and up to date information about the use for which the article/mixture is intended and about any conditions necessary, to ensure that it will be safe without risks to safety or health at all times. The employer therefore will require the GHS classification and the equivalent of a SDS to complete his necessary occupational risk assessments. The Hazardous Substances Ordinance in Germany is an example of a more prescriptive ‘civil law’ legislative instrument, which contains requirements for employers in terms of information gathering and risk assessment. The employer may carry out his occupational risk assessment based on the hazardous classification of the substances/mixtures and information available in SDSs. For substances/mixtures which have not been classified and labelled, for example those of which are manufactured in house, the employer shall himself classify these substances/mixtures according to the CLP Regulation to at least identify the risks to workers present. 4. GHS is intrinsically linked with the transportation regulations for dangerous goods The UN Recommendations on the Transport of Dangerous Goods, Model Regulations define the safety requirements for transport of dangerous goods, which in Europe are legislatively implemented with respect to: Internationally, these Model Regulations are implemented or in the process of being implemented by many countries, along with the following international codes based on the same Model Regulations: Therefore, it is vital for suppliers to obtain the correct hazard classification of their substances or mixtures in order to ensure compliance with these Regulations. If a substance being transported is classified incorrectly as non-hazardous or with the wrong hazard classification, it could mean legal consequences or at worse an extremely unfortunate accident, as a result of not being packaged or labelled correctly for transportation. 5. Correct identification of hazardous waste The properties of waste which render it hazardous are listed in the EU Directive 2008/98/EC on Waste. The attribution of the hazardous properties listed in this Annex is based on the criteria defined in the CLP Regulation. Therefore it is necessary to obtain the correct GHS classification of a substance/mixture constituting the waste in order to identify its status as hazardous waste or not. 6. Seveso Directive and International Convention on Accidents In 1992, UNECE adopted the Convention of the Transboundary Effects of Industrial Accidents as part of a focused effort to prevent industrial accidents and their transboundary effects. This shares considerable similarity to the EU’s Seveso Directive on control of major accident hazards, which appeared initially in 1982 and in its latest Seveso III format, has since June 2015 been based exclusively on GHS classifications (Directive 2012/18/EU on the control of major-accident hazards involving dangerous substances). The scope of this Seveso Directive applies to both dangerous substances present, dangerous substances anticipated to be present (i.e. during manufacturing) and dangerous substances which may be generated during loss of control of the processes, including storage activities. Therefore, one really cannot escape the obligation to correctly classify dangerous substances on site, such as occurs when a raw material is diluted with water to a mixture of lower concentration. What is the classification of this mixture and does it contribute to the thresholds defined in the Directive for applicability of the legislation? Indeed, the correct identification of substances and mixtures, with the subsequent maintenance of inventories below these defined thresholds, may enable an operator to remain outside the more stringent requirements of the legislation or even outside it entirely, which after all is inherently safer for man and the environment.


The above only provides a snapshot of the relevance of abiding by GHS, which is spreading with great success and proving that such chemical safety initiatives need not and must not stop at borders. However, it does require considerable attention to detail. The system may to a good degree be harmonised, but it is legally interpreted with some differences in some jurisdictions. Furthermore, as to what is a right classification, harmonised classifications under REACH are limited; some degree of self-classification can rarely be avoided, which requires considerable attention to detail. Not least as the data on chemical hazards from the raw material suppliers can be limited and indeed their classifications for the same chemical can differ. In particular for self-classification of mixtures as hazardous to the aquatic environment, data can often be missing or conflicting, while at the same time the relevant threshold for these dangerous substances can be as low as 100 tonnes for implementation of Seveso. Áine Monaghan BSc MSc is EHS consultant with PM Group in Dublin. See: