The Environment Agency is considering legal action against Huntsman Polyurethanes in Teesside for a potential breach of its environmental licence over benzene emissions — a failure that counts as a criminal offence under UK law. The regulator told the Guardian it is reviewing further enforcement steps with its legal team and has alerted the UK Health Security Agency and the Health and Safety Executive to assess risks to public and worker health The Guardian, 2026-08-04.

Huntsman Polyurethanes makes chemical building blocks for plastics at the Teesside chemical cluster in Redcar, North Yorkshire. It is part of Huntsman Corporation, a publicly traded global chemicals company that reported $6 billion in revenue in 2025. Its Wilton site supplies aniline — a key input for polyurethanes — to markets worldwide The Guardian, 2026-08-04. The facility operates under environmental permit EPR/BS8656IX and holds Top Tier status under the Control of Major Accident Hazards (COMAH) regime, which means it is subject to joint inspections by the Health and Safety Executive and the Environment Agency. COMAH is a UK regulatory framework designed to prevent major accidents involving dangerous substances and to limit their consequences if they do occur Environment Agency consultation, 2024-01-11.

The benzene problem traces to 2023, when Huntsman shut down a process that had been reducing its benzene air emissions and replaced it with an alternative method run by a third party. Environment Agency documents show the new process 'periodically paused', causing benzene to vent directly into the air. The Agency knew about the problem in 2023 but did not investigate until 2026. Agency records show benzene emissions from the site rose from 13 tonnes in 2022 to 17 tonnes in 2024 The Guardian, 2026-08-04.

Benzene is classified as carcinogenic to humans and causes leukaemia. The World Health Organization states there is no safe level of exposure. In a March 2026 inspection report, the Environment Agency recorded several permit breaches tied to the emissions. Following that inspection, Huntsman was told to carry out dispersion modelling — a technique that uses computer simulations to predict how pollutants spread through the air — to assess the impact. The modelling found 'significant' breaches of legally binding air quality standards in every scenario considered. In one scenario, benzene emissions were predicted to exceed the 24-hour air quality limit by 933% The Guardian, 2026-08-04.

The Agency's internal review of that modelling found the impacts to be 'not insignificant' but concluded that predicted environmental concentrations remain below the relevant environmental standards. A Huntsman spokesperson said the benzene emissions were not illegal and were 'fully compliant with our permit conditions' The Guardian, 2026-08-04. David Santillo, a senior scientist with the Greenpeace Research Laboratories at the University of Exeter, described the emissions as 'very significant' and called the Agency's slow action a 'travesty' The Guardian, 2026-08-04.

Separately, the Environment Agency published a draft decision advertisement in March 2026 for a variation of Huntsman's environmental permit concerning direct emissions of chromium and nickel to a receiving water body gov.uk, 2026-03-20.

The enforcement threat arrives against a precarious operational backdrop for the Teesside site. In March 2026, Peter Huntsman, the US owner of the Huntsman site, said he would close the facility if energy costs stayed high for the following three months The Guardian, 2026-03-15. The BBC reported that Huntsman is considering closing one of its last remaining UK sites because of a 'hostile business environment', a move that would risk about 100 jobs BBC, 2026-03-16.

The broader context here is a tension between the UK's industrial competitiveness agenda and its environmental enforcement framework. The Agency's three-year gap between becoming aware of the problem and investigating it, set against a four-tonne increase in annual benzene emissions, raises questions about regulatory capacity at Top Tier COMAH sites where operational changes can shift emissions profiles. The discrepancy between Huntsman's compliance claim and the Agency's documented permit breaches, alongside the 933% exceedance scenario in the company's own modelling, points to a contested regulatory boundary that legal proceedings would need to resolve. For a site whose owner has already signalled potential closure, the enforcement decision carries consequences that extend beyond the facility's fence line into the wider debate over the future of the UK's remaining petrochemical manufacturing base.