12. Chemicals and priority substances

This section describes the range of mechanisms that control the use, reduction and cessation hazardous chemicals and priority substances.

The WFD Regulations provides for identification of priority substances. The regulations require progressive reduction of discharges, emissions and losses of these substances and, for a subset of priority hazardous substances, cessation or phasing-out of discharges, emissions and losses within 20 years. It also requires environmental quality standards to be used as criteria for the assessment of good chemical status for surface water bodies. The initial list of priority substances was agreed in 2001.

The initial list contained 33 priority substances (or groups of substances), of which 13 were identified as priority hazardous substances.

Further standards were implemented in 2015. There are now 45 priority substances of which 21 are priority hazardous substances. This number includes 11 new substances for which the standards came into force in 2018.

Objectives to achieve good chemical status and for progressive reduction of priority substances and cessation of priority hazardous substances are subject to disproportionate cost and technical infeasibility considerations.

A further requirement of the Environmental Quality Standards Directive is to take measures to ensure, subject to WFD Article 4, that concentrations of certain priority substances that tend to accumulate in sediment or biota (or both) do not significantly increase. The WFD (Standards and Classification) Directions (England and Wales) 2015 has a requirement to establish an inventory of emissions, discharges and losses of the priority substances for each river basin district.

There is a requirement to identify substances that qualify as ‘specific pollutants’, that is, substances that are considered to potentially cause environmental problems, but have not otherwise been identified as priority substances requiring action. Environmental quality standards are derived for these using a similar process to that for priority substances. An initial list of ‘specific pollutants’ was set out in directions from government to the Environment Agency. The initial directions were revoked and replaced by the Water Framework Directive (Standards and Classification) Directions (England and Wales) 2015. The new directions introduced revised standards for some ‘specific pollutants’ and introduced new Specific Pollutants to the list. The Environment Act 2021 sets out new powers to allow the Secretary of State to make changes to substances and standards related to the chemical status of surface water or groundwater.

Since June 2009, risks to human health and the environment (including the water environment) have been assessed for many chemicals under the EC REACH (Registration, Evaluation, Authorisation and restriction of Chemicals) Regulations. United Kingdom REACH commenced in 2021 and allows control of the use and bringing to market of many chemicals within the United Kingdom (see section 12.3).

Many of the mechanisms listed in section 6 (point source pollution), 7 (diffuse pollution) and 12 (Plant Protection Products) can be used to avoid or limit pollution from priority substances and specific pollutants. Other available mechanisms for managing these substances are given below.

Measures for managing substances:

  • controls on point or diffuse sources of pollution under the Environmental Permitting Regulations (England and Wales) 2016; places controls on discharges or disposals of substances; eliminates, reduces and renders emissions harmless
  • Control of Pollution Act 1974; bans use of tributyltin (TBT) on boats less than 25m long
  • the Merchant Shipping (Anti-Fouling Systems) Regulations 2009; made it an offense from 1st December 2009, for vessels’ hulls to be treated with organotin substances (for example TBT) and for vessels in United Kingdom waters from bearing organotin compounds, unless they have a barrier coating
  • International Convention on the Control of Harmful Anti-fouling Systems on Ships of the International Maritime Organization 2008; Introduces an international ban on use of TBT as an antifoulant on boats
  • world-wide treaty on Persistent Organic Pollutants; bans marketing and use of these substances as implemented by the Persistent Organic Pollutants Regulations 2007 (as amended) bans use of particular substances (persistent organic pollutants) in the United Kingdom

12.1 Other approaches

The European Union (EU) mercury strategy and associated EU and United Kingdom mercury regulations and the work of the OSPAR Commission have reduced the use of mercury in industry, including a ban on mercury thermometers (The 1992 OSPAR (Oslo-Paris) Convention is the current instrument guiding international cooperation on the protection of the marine environment of the North-East Atlantic.

The Environment Agency’s Memorandum of Understanding with the Coal Authority deals with the prevention of new discharges and remediation of existing discharges from abandoned coal mines, exchange of information, research and to ensure (as far as possible) operators deal with potential pollution from closure of licensed coal mines. Discharges from closed coal mines typically contain iron and manganese (both are Specific Pollutants).

Abandoned metal mines impact up to 1,500km of rivers in England, and are a significant source of metals particularly cadmium (Priority Hazardous Substance), lead and nickel (Priority Substances), zinc and copper (Specific Pollutants). The Environment Agency, Defra and the Coal Authority have been working together since 2011 to identify priority discharges and implement remedial measures in England through the WAMM (Water and Abandoned Metal Mines) Programme.

There are several national initiatives to help minimise the environmental risks from pesticides and prevent further environmental damage. These include the pesticide Voluntary Initiative, the Amenity Forum and other pesticide product stewardship campaigns, Catchment Sensitive Farming and water company catchment schemes. Registration of users and certificates of competence under BASIS minimises the environmental risks from sheep dip and other chemicals and prevents further environmental damage.

12.2 Plant Protection Products (Pesticides) Regulation

The Official Controls (Plant Protection Products) Regulations 2020 (legislation.gov. aims to prevent adverse impacts from plant protection products by controlling their marketing and use. Plant protection products include herbicides (weed killers), insecticides, fungicides, molluscicides (slug and snail killer) and other pesticide products used to protect plants. Changes are made to enact the requirements on leaving the EU in The Pesticides (Amendment) Regulations 2019.

Active substances must be approved for use in plant protection products. To gain approval, the producers must submit a dossier identifying the active substance (and a plant protection product which contains it); its physical and chemical properties; its effects on target pests; and any possible effects on people, the environment and non-target plants and animals. The dossiers are evaluated by the Chemicals Regulation Directorate of the Health and Safety Executive and a decision is made on whether the substance can be approved for use and any conditions on use should apply across Great Britain. Individual plant protection products which contain those active substances must be authorised at United Kingdom level before they can be placed on the market or used. Approved active substances and authorised plant protection products are regularly reviewed, to ensure that they continue to meet modern standards of safety.

The Official Controls (Plant Protection Products) Regulations 2020 applies directly to Great Britain. These are underpinned by the Plant Protection Products (Miscellaneous Amendments) (EU Exit) Regulations 2019, the Plant Protection Products (Fees and Charges) (Amendment) Regulations 2016 and the Plant Protection Products (Sustainable Use) Regulations 2012 administered in the United Kingdom by the Chemicals Regulation Directorate, part of the Health and Safety Executive. The Plant Protection Products (Sustainable Use) Regulations 2012:

  • contributes to reducing the impact of plant protection products on human health and the environment
  • aims to achieve a more sustainable use of plant protection products
  • encourages a significant overall reduction in risks and hazards of using plant protection products consistent with necessary crop protection
  • the regulations contain specific measures to protect the aquatic environment and drinking water and require a reduction of pesticide use or risks in specific areas, including protected areas under the WFD

The regulation establishes a framework for promoting ‘best practice’ in the storage, use and disposal of pesticides, and their packaging. Main features include:

  • establishment of national action plans
  • compulsory testing of spray machinery and certification of spray operators, distributors and advisors
  • a ban, subject to derogations, on aerial spraying
  • special measures to protect the aquatic environment, public spaces and Special Conservation Areas
  • minimising risk of pollution through handling, storage and disposal; and promotion of Integrated Pest Management

The United Kingdom’s National Action Plan.

The Chemicals Regulation Directorate of the Health and Safety Executive is the competent authority for overseeing implementation of the Plant Protection Products (Sustainable Use) Regulations 2012.

You can find further information at Pesticides-Health and Safety Executive (HSE).

12.3 Regulation on Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH)

The REACH etc. (Amendment etc) (EU Exit) Regulations (as amended) aims are to:

  • provide a high level of protection for human health and the environment from the use of chemicals
  • make the people who place chemicals on the market (manufacturers and importers) responsible for identifying, understanding and managing the hazards associated with their use
  • encourage the use of alternative methods for the assessment of the hazardous properties of substances, for example, through the Quantitative Structure-Activity Relationships (QSAR) Toolbox software application and read across

United Kingdom REACH applies to substances manufactured or imported into the in quantities of 1 tonne per year or more. Generally, it applies to all individual chemical substances on their own, in preparations or in articles (if the substance is intended to be released during normal and reasonably foreseeable conditions of use from an article). Some substances are specifically excluded, for example, radioactive substances, substances under Customs supervision, the transport of substances, non-isolated intermediates, waste and some naturally occurring low hazard substances.

Some substances, covered by more specific legislation, have tailored provisions, including human and veterinary medicines, food and foodstuff additives and plant protection products and biocides. Others have tailored provisions within the United Kingdom REACH legislation, as long they are used in specified conditions, such as isolated intermediates and substances used for research and development.

The competent authority for United Kingdom REACH is the Health and Safety Executive, supported by others, in particular the Environment Agency. Implementation of United Kingdom REACH is by the REACH Enforcement Regulations 2008 and is phased with registration deadlines up to 28 October 2027, depending on the annual tonnages involved.

Find further information on REACH.

12.4 Veterinary and medicinal products

Veterinary and human medicinal products in the United Kingdom are regulated by the Defra under the Veterinary Medicines and Residues (Amendment) (EU Exit) Regulations 2020

The Veterinary Medicines Directorate (VMD) is an Executive Agency of Defra. The VMD is the competent authority responsible for regulating the issue and use of veterinary medicines in the United Kingdom, in accordance with European Community and United Kingdom legislation.

You can find further information on the Veterinary Medicines Directorate website.

The Veterinary Medicines Directorate of Defra is responsible for preparing opinions on questions concerning medicines for veterinary use. In addition, the Veterinary Medicines Directorate is responsible for conducting the assessment of veterinary medicines for which a United Kingdom marketing authorisation is sought. Furthermore, the Veterinary Medicines Directorate prepares scientific guidelines in consultation with the competent authority to help applicants prepare marketing authorisation applications for medicinal products for veterinary use.

Environmental impacts assessments are carried out in 2 phases. In phase one the potential for environmental exposure is assessed based on the intended use of the veterinary medicinal product. Where a potential environmental risk is identified, a detailed procedure of environmental risk assessment is carried out under phase 2. This provides a common basis for the testing of veterinary medicinal products between the United Kingdom, the EU, Japan, United States of America, Canada, Australia and New Zealand.

12.5 Biocidal Products Regulation (BPR)

Biocides in the United Kingdom are governed by The Chemicals (Health and Safety) and Genetically Modified Organisms (Contained Use) (Amendment etc.) (EU Exit) Regulations 2020 which amend the 2019 regulations concerning the making available on the market and use of biocidal products, applies to substances that are used to destroy or prevent the action of harmful organisms by chemical or biological means.

Common examples of biocidal products include rodenticides, disinfectants, wood preservatives and insect repellents. They are used in a wide variety of industries to control organisms such as viruses, bacteria, fungi and animals. The main purpose of act is to:

  • harmonise the market for biocidal products, their active substances and product authorisation
  • provide a high level of protection for people, animals and the environment from the use of biocidal products; authorisation under BPR requires submission and evaluation of data on:

    • chemistry of the substances concerned
    • their toxicity to humans
    • their toxicity and fate in the environment

The Health and Safety Executive is the competent authority for EU BPR, which is directly acting. The regulation is enforced by both the Health and Safety Executive and some aspects by local authority inspectors and trading standards officers.

There are 22 different biocidal product types which include disinfectants, preservatives, pest control and speciality biocides such as antifouling products and embalming and taxidermist fluids.

You can find further information at Biocides – HSE.