International Paint Ltd was yesterday found guilty after a banned chemical entered the Yealm estuary, in Devon, from its site at Newton Ferrers.

The company, owned by multi-national AkzoNobel, appeared before Plymouth Crown Court, where, at the end of a nine-day hearing, were found guilty on two charges. The company had denied both offences relating to the discharge of hazardous waste from a tank located on the quay at its Newton Ferrers paint testing facility. The case was adjourned until January for sentencing.

The court heard that the Environment Agency launched an investigation after the company tried to sell the premises in 2015 and possible pollution was reported to the Environment Agency by Simon Friend of Red Earth Developments. International Paint Ltd manufactured paints, including anti-fouling paints for ships, and had run a testing facility on the River Yealm at Newton Creek near Newton Ferrers since 1928. The estuary is a Special Area of Conservation due to its rich flora and fauna.

Since the 1970s, formulations containing tributyltin (TBT) had been used as a coating to prevent the build-up of organisms and plants on ships’ hulls. But it proved to be so toxic to the wider marine environment that it was banned from use on small vessels in the UK in the late 1980s and was banned completely worldwide during the 2000s. One drop of TBT in an Olympic sized swimming pool equals one part per trillion (PPT). The safe level of TBT is 0.2 PPT or a fifth of a drop.

The Environment Agency’s investigation found evidence that the chemical, along with copper, arsenic and mercury, had been present in sediment in the tank at the site and some of the sediment had escaped out into the estuary. A bung on another tank was found to have come out leaving it open to the estuary, before it was eventually permanently sealed with concrete. The company denied having caused the discharge of the sediment into the estuary but did not answer what had happened to it.

Leading expert, Dr Michael Waldock, whose work led to the banning of TBT, carried out a review of sample analysis results from sediment from the tank and from the adjacent estuary for the Environment Agency. He found that nine out of 11 samples exceeded the safe limit for TBT and that, close to the site, one sample contained 80,000 times the safe level. He concluded that the TBT levels in the estuary were sufficient to have had a major toxic effect on marine life there.

James Wimpress of the Environment Agency said following the hearing: “The company owned by a multi-national firm, and with a turnover of £134m in 2020, failed in its duty of care to the environment. The company denied any wrongdoing during the investigation and throughout the trial. We are extremely pleased with the outcome and hope this serves as a warning to other companies that we will not hesitate to pursue those that act without regard to their responsibilities.”