A global chemicals company has been fined £400,000 after a worker narrowly escaped serious injury in a high-pressure steam release incident at its site in Huddersfield.

Syngenta Ltd was sentenced after the 59-year-old contractor – working under its control and direction – had been carrying out unsafe maintenance work. The man had been working as a mechanical fitter on 6 November 2023 when the incident took place, resulting in the company reporting it to the Health and Safety Executive (HSE) as a dangerous occurrence. The incident involved a release of high-pressure steam as he went about his job.

The company operates a large agrichemicals production site where some of the production plants rely on high pressure steam to manufacture products. The HSE investigation found that the incident occurred during the planned replacement of a faulty steam trap on small-bore pipework.

Steam traps are devices that automatically remove condensate (water) and air from the high-pressure steam system. There was a sudden failure of the valve used to isolate the work location from the steam, and this resulted in the uncontrolled high-pressure release.

The HSE investigation also revealed several failures with the system of work in operation. These included:

• The isolation valve failed when the mechanical fitter was separating a bolted flange by cutting the bolts using a battery powered reciprocating saw.
• The isolation valve and flange bolts were affected by corrosion and were in a poor condition.
• Due to widespread corrosion of flange bolts on the steam distribution system, it was considered necessary to routinely cut bolts rather than unscrew them using a spanner.
• Cutting flange bolts reduces the ability to control any unexpected, trapped material or pressure remaining in the pipework.

Syngenta Ltd pleaded guilty to having failed to ensure that the isolation valve and flange bolts were maintained in an efficient state, in efficient working order and in good repair – as required by Regulation 5(1) of the Provision and Use of Work Equipment Regulations 1998 (PUWER) – HSE.

In addition, there was an issue with the company’s documented risk assessment procedure in place before such maintenance work was undertaken. It was routine for Syngenta to carry out maintenance work on small-bore pipework of the high-pressure steam distribution system, using a single method of isolation.

HSE’s published guidance about on this subject (The safe isolation of plant and equipment – HSE, HSG253) emphasizes that using a method of double isolation is safer. The risk assessment documents in place failed to appreciate the increased risk involved in relying on a single method of isolation when there was known corrosion of the work equipment. Syngenta Ltd also pleaded guilty to having failed to make a suitable and sufficient assessment of the risk involved in carrying out the specific maintenance work described as required by Regulation 3(1) of the The Management of Health and Safety at Work Regulations 1999.

Syngenta Ltd, whose head office is at Bracknell, Berkshire pleaded guilty to the two offences at Leeds Magistrates’ Court on 28 January 2026 and was fined £400,000 and ordered to pay costs of £8,288.

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.”

This HSE prosecution was brought by enforcement lawyer Iain Jordan and paralegal officer Zara Salman.

 

Further information:

1. The Health and Safety Executive (HSE) is Britain’s national regulator for workplace health and safety. We are dedicated to protecting people and places, and helping everyone lead safer and healthier lives.
2. More information about the legislation referred to in this case is available.
3. Further details on the latest HSE news releases is available.
4. Relevant guidance can be found here: The safe isolation of plant and equipment – HSE
5. HSE does not pass sentences, set guidelines or collect any fines imposed. Relevant sentencing guidelines must be followed unless the court is satisfied that it would be contrary to the interests of justice to do so.  The sentencing guidelines for health and safety offences can be found here.