The incident occurred on 6 November 2023 while a 59-year-old contractor, working under the company’s control and direction, was replacing a faulty steam trap on small-bore pipework. The work involved separating a bolted flange, with bolts cut using a battery-powered reciprocating saw. HSE said the isolation valve failed suddenly, leading to an uncontrolled release of high-pressure steam that narrowly avoided serious injury.
What HSE Found During Its Investigation
According to HSE, the isolation valve and flange bolts were affected by corrosion and were in poor condition. The investigation also noted that cutting flange bolts had become a routine approach on the steam distribution system because corrosion made it difficult to unscrew bolts. That matters because cutting reduces the ability to control unexpected trapped material or residual pressure in the pipework when a flange is opened.
HSE also highlighted shortcomings in the risk assessment process used before maintenance. The company’s documents did not reflect the increased risk of relying on a single method of isolation when corrosion was known, and HSE referenced its guidance on the safer approach of double isolation for plant and equipment.
Court Outcome And Compliance Implications
Syngenta pleaded guilty to offences relating to the condition of work equipment and the adequacy of risk assessment. The company was sentenced at Leeds Magistrates’ Court on 28 January 2026, receiving a £400,000 fine and being ordered to pay costs of £8,288.
For operators running high-pressure steam networks in chemical and process manufacturing settings, the case is a reminder to treat corrosion management as a safety-critical control, not a maintenance backlog. Where site practices have evolved to “work around” degraded equipment, organisations should step back and reassess whether those practices have effectively changed the risk profile and require stronger controls.
Summary
HSE’s prosecution demonstrates how equipment condition, isolation choices and risk assessment quality intersect in high-energy systems. Companies maintaining steam pipework should ensure valves and fasteners are in good repair, confirm isolation methods are appropriate for the hazards, and align work planning with recognised guidance to reduce the chance of an uncontrolled release.