Stronger chemical safety laws needed to protect UK food and waters – with 95% of rivers polluted by harmful biocides

4 July 2025

Environment groups are warning that new chemical deregulation proposals from the Health and Safety Executive could have far-reaching damaging implications for our health, environment and for trade.

The groups are urging the Government to abandon proposals which would end mandatory renewal processes for biocide chemicals and remove requirements to respond to new EU hazard classifications. They warn these shifts would weaken consumer and environment protections and have implications for contamination risks for UK rivers, food and products for sale. The groups are also urging the Government to recognise the risks that diverging from the EU’s approach to chemical regulation could be a major barrier to aligning with EU trade requirements in future, which could harm the economy. The calls come as new research reveals UK waters are almost universally contaminated with biocides.

Products that contain biocides include: disinfectants and cleaning sprays, insect repellents, insect killer sprays, rat poisons, wood preservers, adhesives, carpets and furniture, construction materials, paints, and paper products. The new Government proposals to weaken chemical regulation could leave biocide products on GB shelves that might be banned elsewhere, or see high-strength products for sale when only weaker versions are allowed in the EU due to toxicity levels. This increases the potential for companies to look to offload more of these products in GB once they can no longer be sold in the EU and elsewhere.

Environmentalists are warning that the Government’s biocide approach will be somewhat at odds with Britain’s recent agreement to dynamically align with the EU on pesticides to remove barriers to trade on agri-food products. UK food production will still be exposed to rodenticides and disinfectants, which are classed as biocides and do not have EU regulation as a backstop. The HSE proposals could potentially be a barrier to aligning on these areas in future, which might have trade implications further down the line.

Moving further away from EU hazard classifications also poses challenges for matching new EU standards on products such as toys which could leave the UK with toys on the market that are banned in the EU due to chemical safety concerns. For example, the UK has yet to adopt EU hazard classifications on Endocrine Disrupting Chemicals (EDCs - which affect hormones) which will be a barrier to the UK adopting the EU’s proposed Toy Safety Directive that will automatically prohibit the use in toys of harmful EDCs to better protect children.

The warnings over weaker biocide rules come as new research is published from Wildlife and Countryside Link and The Rivers Trust.[1] The research analysed official Environment Agency water quality data within drinking water safeguard zones for overall biocide presence, with more detailed analysis on the presence of 7 key biocides in English rivers (Azoxystrobin, Diuron, Picaridin (Bayrepel), Propiconazole, Thiabendazole, Triclosan and N,N-diethyl-meta-toluamide - DEET), and shows:

• High presence in drinking water safeguard zones: Across all surface drinking water safeguard zones the research identified that 51 unique biocides were present between 2019 and 2024, with an average of 4 biocides detected at each sampling site.
  
• High presence in river sites: At least one of seven key biocide compounds was detected at a worrying 95% (113 out of 119) of river sites tested between 2019-2024 in the Environment Agency’s LC-MS database.
  
• Triclosan (found at 78% of river sites), Propiconazole (in 65% of river sites) and Diuron (in 63% of river sites) were the most commonly detected biocides in the LC-MS database. DEET was analysed in a second Environment Agency database and was detected at 74% of sites.
  
• The river sites where the highest number of biocides were detected were: the River Lugg in the Midlands; the River Nene in Cambridgeshire; River Waveney in Ellingham, Norfolk; The River Ouse at Roxton, Bedfordshire; River Ouse at Naburn, Yorkshire; River Teme at Powick, Worcestershire; The River Irwell, near Bolton, Lancashire; A tributary of the River Flit near Flitwick; River Douglas near Rufford, Lancashire; River Ivel, Tempsford, Bedfordshire; Sincil Dyke, Washingborough, Lincolnshire, and the River Blyth, Bedlington, Northumberland.

Richard Benwell, CEO of Wildlife and Countryside Link, said: “The growing protection gap between the UK and the EU on chemicals is at risk of becoming a canyon. The simple fact is the UK doesn’t have the resources to replicate the multi-billion pounds worth of chemical risk analysis the EU does every year. And these new proposals jeopardise consumer and environmental protections, and potentially trade with the EU as product requirements diverge. Rather than dropping vital chemical risk protections because Government Departments are overstretched we need to be making the most of the existing evidence on risks to people, food, rivers and to wildlife. That means aligning with the EU over what chemicals to ban and restrict.”

Dr Rob Collins, Director of Policy and Science at the Rivers Trust, said: “Finding biocides in almost every river tested is alarming - this is a really high presence rate. Though it’s not possible from this data to determine the level of harm they are having on our rivers and wildlife, these are hazardous chemicals, designed to kill organisms. Chemical pollution in our rivers is just as harmful as sewage pollution yet is largely under the radar and under-prioritised by the Government. That needs to change. Alignment with the EU is the quick, sensible solution to bridge the chemical protection gap in the UK.”

Chloe Alexander, Senior Campaigner, CHEM Trust quote: “This is no time to be deregulating British chemical safety laws when levels of harmful chemicals entering our environment are already above safe levels and look to increase.

“Hazard classifications are essential, as they identify substances which are harmful to our health, the environment or both. But these proposed changes, will in our view damage Great Britain’s reputation for having high product standards and weaken protections for consumer and worker health and safety and for the environment.

“We urge the Minister not to bring in these measures, and instead take steps to unilaterally align with the EU. This would prevent our health and the environment from being damaged by harmful substances and products that under these proposals could continue to remain on the market in Great Britain, despite being banned in the EU.”

Ruth Chambers, senior fellow, Green Alliance commented: “With toxic chemicals polluting our rivers and our bodies, we should be strengthening safety protocols, not abandoning them. Successive governments pledged that Brexit would not come at the expense of environmental protections. Ministers must now follow through on that promise and scrap these regressive and damaging proposals.”

Biocide chemicals control organisms, such as bacteria, viruses, insects, rodents and mould. While they can have useful properties, many can also be toxic to wildlife, affect public health and harm water quality when washed away or released into our waters. They have known links to health issues such as cancers, foetal development, liver function, and skin and eye irritation (with creosote use being restricted after links to cancers, for example). Therefore, it is vital that the risks of these products are regularly assessed.

The Health and Safety Executive (HSE) proposals would leave many products going without the checks and balances needed - including revising concentrations permitted for sale as new evidence emerges. The proposals would be a significant shift that weakens consumer and environmental protection. This follows the decision in 2022 to extend the timeframe for processing biocidal product applications by 5 years to 2027. This means that products not approved in the EU since 2022 can continue to circulate freely on the GB market – exposing GB consumers to greater safety risks, especially if those goods are increasingly dumped on the GB market.

This is just one of many areas where chemical protections in the UK are falling behind that of the EU. Since leaving the EU’s chemical regulation system the UK has registered no Substances of Very High Concern for additional action (compared to 38 in the EU), has adopted no new bans or restrictions (compared to 13 in the EU) and at the same time the HSE has deprioritised 12 substances which the EU has current or planned restrictions for.[4] 

This is alongside the fact that not one river in England is in good chemical health with harmful chemicals such as PFAS found at concerning levels in rivers and drinking water nationwide, and known harmful cocktails of chemicals found in over 1,600 rivers and groundwater sites across the country. Along with today’s biocide pollution findings, a growing wealth of evidence on the chemical pollution in our rivers is concerning for both public and wildlife health.

HSE says these changes are needed to address the lack of regulatory capacity to meet mandatory timed renewal dates and other requirements. But Environment groups say there is no need to abandon vital regulation of harmful biocides and are urging the Government to instead:

• Fulfil its pre-election promise to align all UK chemical regulation with that of the EU - including aligning on biocide regulation. This would allow the UK to benefit from the billions of Euros of expertise the EU invests each year in identifying substances that pose risks and what measures are needed to control them, which the UK cannot afford to replicate. And would provide a consistent approach across Government, with dynamic pesticide alignment already agreed with the EU
  • HSE should instead automatically adopt EU decisions on biocides - particularly its decisions not to approve biocidal products and/or active ingredients used in them after assessing the risks posed by these substances and availability of alternatives
  • On wider chemical regulation, alignment would allow Defra to utilise the resources currently allocated to unnecessary duplicative assessment of processes already undertaken in the EU, to areas such as better monitoring of pollutants in rivers and better enforcement of pollution laws.

ENDS

Notes to editors:

1. The Rivers Trust and Wildlife and Countryside Link analysed official Environment Agency data for:
   1. Presence of biocides in surface drinking water safeguard zones between 2019 - 2024. These zones are catchment areas where actions and measures will be targeted to address water contamination and avoid or minimise extra treatment needed by water companies.
   2. Presence of 7 key biocides, including analysis of 6 biocides in the Liquid chromatography-mass spectrometry (LC-MS) database, with a further biocide N,N-diethyl-meta-toluamide – DEET (used in high-strength insect repellants) was analysed from data in the Gas chromatography-mass spectrometry (GC-MS) database. Data from between 2019 and 2024 was analysed.
2. All samples were evaluated on a presence/absence basis only due to the semi-quantitative nature of the laboratory analysis.
3. Listed below are the 6 biocides analysed in the LC-MS database. It is worth noting the same chemicals are also often found in cosmetics, personal hygiene products, plant sprays & weedkillers but these uses are regulated differently and would not be affected by biocide regulation:
   1. Azoxystrobin is a broad spectrum systemic fungicide used as a biocide in mould and mildew repellent boarding and other products, and as a pesticide in agriculture and in domestic products surf as turf weedkiller,
   2. Diuron is used in paints, coatings, plasters and adhesives such as superglue, and as a pesticide in weedkillers.
   3. Picaridin (Bayrepel) - is a newer insect repellent, first made in the 1980s, and unlike DEET is odourless.
   4. Propiconazole is used in wood preservatives and construction materials such as flooring, tile, sinks, bathtubs, mirrors, wall materials/drywall, wall-to-wall carpets, insulation, and playground surfaces.
   5. Thiabendazole is primarily used to control mould. It is used in wood preservatives, carpets, paint and paper products, in adhesives and other craft materials (including those that might be used by children like glitter glues), alongside use in some veterinary medicines and pesticides
   6. Triclosan prevents the growth of bacteria and fungus. It is used as a biocide in household disinfectants (particularly products targeted at bacteria and mould), dish detergents, soap and hand sanitizer and is also used in a variety of common household products, including cosmetics, mouthwashe,, toothpastes, and deodorants. Unilever opted to remove Triclosan from its products due to consumer demand.
4. The EU continues to make progress in protecting the environment and public health from harmful chemicals, while the UK has been moving more slowly and demonstrating less ambition. This is set out in a table of the differences in protections - https://chemtrust.org/divergence-table/
   1. Since leaving the EU’s chemical regulation system the UK has not identified a single Substance of Very High Concern (SVHC) compared to 38 being added to the EU’s list. The EU list carries immediate obligations on companies to provide sufficient information to customers/consumers on safe use and puts substances in line for further regulatory attention.
   2. The UK has also yet to adopt a single new ban or restriction on a harmful substance, compared to 13 new restrictions adopted in the EU in this period. So far, the UK has initiated (but not adopted ) 3 restrictions - on harmful substances in tattoo ink, lead in ammunition and PFAS in firefighting foam. This compares to 24 initiated by the EU. In 2023, the HSE deprioritised 12 harmful substances on which the EU has either adopted or initiated a restriction, including PAHs used in synthetic football pitches and playgrounds that are linked to increased cancer risk.
   3. Harmful substances on the ‘authorisation list’: The UK has so far added no new substances to its harmful substances authorisation list, compared to five added to the EU’s list, including Tetraethyllead (TEL) in aviation fuel. The Health & Safety Executive (HSE) declined to add TEL to the authorisation list, despite health impacts on communities living close to small aircraft sites. Companies cannot use or manufacture any substance on the list unless given ‘authorisation’ by the regulatory agency.
   4. The UK has fallen behind and failed to match EU protections from PFAS ‘forever chemicals’, which has introduced new statutory standards for PFAS in food and drinking water, banned all PFAS used in paper and cardboard food packaging from August 2026. The UK is also focussing on just a few hundred PFAS, rather than the EU’s proposal to phase out the manufacture and use of all PFAS.