Steam release safety is critical in industrial plants. Syngenta Ltd, a global chemicals company, was fined £400,000 and ordered to pay costs of £8,288 after a dangerous high‑pressure steam release at its Huddersfield site.
Investigation details
The incident occurred on 6 November 2023 when a mechanical fitter was replacing a faulty steam trap on small‑bore pipework. While cutting corroded flange bolts with a battery‑powered reciprocating saw, the isolation valve failed, allowing high‑pressure steam to escape.
High‑pressure steam systems are integral to many chemical manufacturing processes, providing energy for heating and reaction control. When not properly isolated, the stored energy can be released instantaneously, creating temperatures above 200 °C that cause severe burns or fatal injuries in seconds. Corrosion of valves and bolts compromises their ability to seal, making regular inspection essential.
Key findings from the HSE investigation
- The isolation valve and flange bolts were severely corroded, compromising their integrity.
- Due to widespread corrosion, it had become routine practice to cut bolts with power tools rather than unscrew them—a method that reduces the ability to control trapped pressure.
- Use of a single method of isolation breached Regulation 5(1) of the Provision and Use of Work Equipment Regulations 1998 (PUWER), which requires equipment to be kept in efficient order.
- The company’s documented risk‑assessment procedure failed to consider the increased risk from relying on a single isolation method when corrosion was known, breaching Regulation 3(1) of The Management of Health and Safety at Work Regulations 1999.
- HSE Inspector David Welsh said: “If a safe system of work had been in place at the site when the maintenance was being carried out, this dangerous incident would not have happened. The company did not appreciate the extent of the risk posed because of the way the maintenance work was being done, and the relatively simple control measures that could have been applied to make it safer. Syngenta not only failed produce an appropriate risk assessment, but also failed to maintain work equipment in a safe condition – which taken together meant that this was a dangerous accident waiting to happen.”
- The case was heard at Leeds Magistrates’ Court on 28 January 2026, resulting in the £400,000 fine and £8,288 costs.
Why this matters to employers
High‑pressure steam is capable of causing severe burns or death within seconds. Proper isolation, regular inspection of valves and bolts, and robust risk assessments are essential to prevent such incidents.
Beyond the immediate health risks, a prosecution can damage a company’s reputation, increase insurance premiums, and lead to costly civil claims from injured workers. Demonstrating proactive safety management helps maintain stakeholder confidence and may mitigate financial impacts.
Improving steam release safety in your workplace
HSE guidance HSG253 recommends using double isolation methods for high‑pressure systems, especially where corrosion is present. This provides a fail‑safe backup if one isolation point fails. Regular toolbox talks ensure workers understand safe isolation procedures and recognise corrosion warning signs before they lead to failure.
How to protect your business
- Conduct a thorough risk assessment for any steam‑system maintenance, ensuring double isolation where corrosion is present.
- Implement regular toolbox talks on safe isolation procedures and the correct use of cutting tools near pressurised systems.
- Develop clear safety policies that require equipment to be maintained in efficient order and inspected at least annually.
- Create detailed method statements for high‑risk tasks such as bolt removal on pressurised plant.
Frequently Asked Questions
What regulation covers equipment maintenance?
Regulation 5(1) of the Provision and Use of Work Equipment Regulations 1998 (PUWER) requires that work equipment be kept in efficient order, efficient working order, and good repair.
Which regulation mandates a suitable risk assessment?
Regulation 3(1) of The Management of Health and Safety at Work Regulations 1999 requires employers to carry out suitable and sufficient assessments of risks to workers and others affected by their work activities.
How often should isolation valves be inspected?
At minimum annually, or more frequently if corrosion is observed. Follow manufacturer guidance and HSG‑253 recommendations on double isolation for high‑pressure systems.
What is double isolation and why does it matter?
Double isolation uses two independent methods to isolate energy sources, providing redundancy if one method fails. HSE guidance HSG253 strongly recommends this for high‑pressure steam systems, especially where corrosion is known.
Source: Major chemical firm hit with £400,000 fine after dangerous steam release