Chemical giant Syngenta has been fined £200,000 after a potentially deadly weedkiller was accidentally released at its Huddersfield plant.

Leeds Crown Court heard at least three and a half tons of highly toxic paraquat escaped from an isotanker while it was being filled on December 12, 2014.

Employee Daniel Morris had accidentally opened a valve which formed part of the coupling apparatus connecting a hose to the tanker, unaware that the dry disconnect coupling was defective.

One of four other valves on the tanker had also not been opened which meant the contents inside, being produced for the Japanese market, had become pressurised.

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Kevin Slack, prosecuting, said when Mr Morris moved a handle because of the defective coupling that valve partially opened and he was immediately sprayed with the paraquat dichloride (PDC) on his face and upper body. Fortunately he was wearing safety glasses and did not swallow any of the substance.

Leeds Crown Court
Leeds Crown Court

He was only feet away from an emergency drench shower where he went immediately to wash off the solution and suffered no injury. Mr Slack told the court ingesting five to 10 millilitres of paraquat dichloride could be potentially fatal.

Another colleague Philip Parkinson who was standing on a gantry near Mr Morris at the time of the leak was also unharmed and was able to ring the site safety fire services.

The escape continued for half an hour until it was closed by a fire auxiliary wearing a full protective suit. By then it was estimated a minimum of 3.5 tonnes had escaped into the air.

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Fortunately the wind blew the material towards storage areas and not towards an internal roadway which was used as an access road and there was no risk to anyone off the site at Leeds Road, Deighton, where some 400 employees work.

He said it was the Health and Safety Executive’s case a maintenance programme should have covered checks on the couplings and that the risk assessment was inadequate.

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Syngenta admitted two charges contravening regulations, failing to ensure that work equipment was maintained in an efficient state and failing to take all measures necessary to prevent a major accident, the firm’s first conviction.

Dominic Adamson representing the company expressed “sincere regret” for the incident that gave rise to this prosecution. He added: Syngenta takes responsibility for health and safety very seriously and the loss of its unblemished track record is a heavy blow.”

He said they accepted there was an omission in their maintenance regime regarding the couplings which had now been rectified.

Syngenta site in Huddersfield

Documentation for employees had also been amended regarding the venting of valves on the tanker, the failure to check the fourth value in this case having led to the build-up of pressure inside.

Imposing the fine and ordering payment of £13,041 costs Judge David Hatton QC said he accepted Syngenta was a responsible company with a good safety record.

He said: “What occurred was a combination of a defect in the coupling for which there was no regime of routine inspection and maintenance and also pressure in the tanker caused by a failure to adequately vent the tanker so pressure arose because the isolation valve below the cow horn adaptor was at the material time closed.”

But the judge said the event could very easily have “had a tragic end, even for example by Mr Morris having ingested a small quantity had he had his mouth open at the time.”

After the case HSE inspector Angus Robbins said: “Serious incidents can occur when failures in risk reduction measures coincide. Such failures are foreseeable and would have been identified and controlled by effective risk assessment and application of risk measure controls.”