Updated August 14, 2024 Authored by Rose Keefe of Dust Safety Science
At 9:11 a.m. on the morning of July 17, 2015, fire bells went off at both the Cheshire Fire and Rescue Service’s Macclesfield and Congleton Fire Stations. Responders noted the location- Wood Treatment Ltd. at Bosley Mill in Congleton- as they rushed into their gear, piled into fire trucks, and left the station for the two-alarm blaze at Wood Treatment ltd, with sirens screaming.
Wood Treatment Ltd. manufactured a variety of wood fibre, wood flour, and wood powder products, which meant that combustible dust was a frequent byproduct and health and safety offence at the wood treatment facility. According to the United States Department of Agriculture, USDA, Wood flour, also known as wood meal, is a finely powdered wood or sawdust that has a similar texture, size, and appearance to cereal flour. It’s made by pulverizing dried wood, often from scraps, using a hammer mill. The wood is then screened so that the particles are small enough to pass through the screen and into a discharge chute. After pulverization, the wood flour is filtered to remove lumps and ensure a consistent consistency. As fire crews raced to the site, they may have anticipated a major event, but probably not the scene of mass destruction and massive explosion that awaited.
A huge fire engulfed the wood flour mill buildings. A crowd stood in the road, dazed and shell-shocked. There were obvious casualties: some people were receiving medical care while others walked around with visible burn injuries.
One Cheshire Fire and Rescue officer described the scene at Wood Treatment ltd, as something “like out of the movies.”
A member of the Urban Search and Rescue team was equally shocked. “The scale of the incident…is unprecedented in this country in the last 10 years,” he later said.
Three explosions destroyed the mill and killed four of its workers.
It took several days before the fires were suppressed enough, for the investigators and rescue teams health and safety, to enter the site. By that point, the wood flour mill at Wood Treatment ltd was completely destroyed by at least three explosions, from wood dust and and a dust cloud. A primary dust explosion occurred within the process, stirring up previously settled dust within the mill, leading to a large secondary dust explosion.
More than 800 tons of rubble were moved and police divers were deployed to underground culverts in an attempt to find missing people alive. Firefighters didn’t leave the wood dust explosion site for over a month.
A dark day in the community; the mill site a war zone.
Officials logged four injuries and four deaths. The dead were mill worker Derek Moore, 62, Dorothy Bailey, 62, William Barks, 51 and Jason Shingler, 38. (Shingler’s body was never found.)
The local Member of Parliament, David Rutley, spent time at the site. He later recalled it was “like a war zone” and described the tragedy as the “darkest day” yet in his time as MP. A fund for the victims and their families was set up by a local councillor. While this measure helped address some of the financial losses, it did not (and never could) compensate for the lives of the four people lost. For justice to take place, the authorities had to step in.
Safety was a long-standing concern at the Bosley Mill.
Combustible wood dust had apparently been a long-standing issue at Wood Treatment Ltd. On February 13, 2013, Sheila Smith, a Director of Risk Management who had been retained by company director George Boden to draw up necessary Health and Safety documentation, sent him an email. Smith, who had been familiar with the wood flour mill for years, expressed concerns over what she called “considerable amounts of wood dust” and “unacceptable dust issues” at the facility, and many health and safety offences.
She was not exaggerating. According to reports, broken-down machinery would have wood dust pouring out of it, sometimes up to a metre high, with previous settled dust. In addition:
- Machines were allegedly not fixed until they were completely broken.
- There was no scheduled maintenance, as the machines were not permitted to stop for that purpose.
- Second-hand parts were applied as temporary fixes.
- There was a reluctance to use approved outside contractors for specialized maintenance.
- Cleaning staff had been cut from a team to one lady: Dorothy Bailey, who died in the explosion.
In 2012, there had apparently been an effort to introduce Fire Risk Assessments for Wood Treatment Ltd. The mill also had spark detection equipment, but it was not functioning properly, compromising its ability to act as an explosion mitigation measure.
Investigators also learned there had been fires at Wood Treatment Ltd in the past. Weeks before the explosion at the wood flour mill, a motor buried under piles of wood dust caught fire. By leaving the issue uncorrected had led to increased health and safety offences and a dust explosion hazard.
Charges of corporate manslaughter were filed against the mill and its directors.
After an extensive investigation by Cheshire Constabulary and the national Health and Safety Executive, Wood Treatment Ltd. was charged with corporate manslaughter in November 2019. In addition, company director George Boden was charged with four counts of gross negligence manslaughter. Two mill managers, Philip Smith and Peter Shingler, pleaded not guilty to an offence under the Health and Safety At Work Act.
When the trial commenced in December 2019, the court heard that before the blast, one worker had branded the mill “a ticking time bomb,” but when staff raised safety concerns they were told, “We’re not making any profits, we need to make money.”
The prosecutor, Tony Badenoch, QC, highlighted a report made in April 2015, following a visit to the site by a risk analyst for insurance purposes. It called for a rolling programme of cleaning to be implemented by July 1 to remove a build-up of wood dust, which, Mr. Badenoch said, could be a “significant dust explosion hazard.”
Inspections revealed a significant dust explosion hazard with risks of devastating secondary explosions.
The report stated, “While normal business operations do not result in significant dust explosions, there is a risk that a small explosion, or other disturbance, may cause settled dusts to become airborne, causing a dust cloud, and perhaps in sufficient concentration to provide an explosive mixture. Typically, ‘secondary’ explosions are devastating.”
Tyler Eastwood told the court that he had visited the wood mill in July 2014 to carry out vibration analysis. He noted that the wood treatment and wood mill site was dusty, with some motors buried in dust, and that vibration in some of the machinery was way outside industry standard. When he visited again in August, he noted some improvements, but by October health and safety conditions had deteriorated again at the wood mill and wood treatment facility.
Conditions at the mill kept deteriorating despite warnings from experts.
One worker said that the rooftop dust collector for ‘Plant 2’ had experienced an explosion so intense that it bent the metal door. Despite this near-miss, he said, “Very few [employees], if any, had been told formally or in any detail about the health and safety offences and risks of explosion in the wood mill.”
A Principal Health and Safety Inspector said that the DSEAR (Dangerous Substances and Explosive Atmospheres Regulations) assessment, although present, was neither suitable nor sufficient.
Mr. Badenoch told the jury, “By its very nature, industrial processing on a site of this kind is dangerous. For that reason, maintenance of machinery and a safe working environment is essential. Failures to adhere to basic maintenance in an industrial environment of this kind can have disastrous consequences.”
He pointed out that the machinery in the Riverside area of the wood flour mill, where waste was routinely discharged into the River Dane, was in such poor repair that the fan had to be chained to the floor to prevent it moving around. Because it was chained to the floor it was called ‘The Riverside Dog.’
During the trial, the following scenarios were presented as possible causes for the tragedy:
- A dust explosion occurred within the process, stirring up settled dust within the wood mill and leading to a large secondary dust explosion.
- A piece of equipment or pipe failed, releasing a dust cloud that made contact with an ignition source and exploded. This event stirred up dust and caused a second explosion.
- A piece of equipment released air or steam, stirring up dust and raising a cloud that exploded.
- The high-voltage switchgear within the mill experienced an explosive failure, stirring up dust and causing a large secondary dust explosion.
Mr. Badenoch told the jurors, “The most likely scenario is one of the first two: an explosion in previously settled dust, leading to a much larger secondary explosion. Whichever of those credible scenarios it is, the prosecution case is that each arose from negligence on the part of the company and the Health and Safety Director (George Boden).”
The prosecution alleged negligence on the part of the company and the Health and Safety Director.
Before the case could go to the jury, it was unexpectedly discharged on January 28, 2021. All that a spokesman from Chester Crown Court would say was that there were “personal issues” concerning the judge. Nearly two weeks later, on February 8, a new judge and jury were sworn in.
Once again, witnesses told their stories. One worker recalled how he and a coworker were fired after he refused to clean an area of the wood mill he believed to be dangerous, and a health and safety offence. He said the dust in the area was up to his knees and made the working areas “unbreathable.”
Another worker said the dust in the Riverside area was sometimes “packed up as tall as me,” adding that he was over six feet tall. He said the cleaner, Dorothy Bailey, did her best but it was “more than a one-person job.”
On March 10, former purchasing manager Alan Seddon told the court that the staff were “fighting a losing battle’ at the mill from 2013 to the time he left in February 2015. He said he had raised concerns with George Boden about the dust, only to be told there was “no money” to address it.
Twelve weeks later, on April 29, the judge directed the jury to find Phillip Smith and Peter Shingler not guilty of any charges. The manslaughter charges against Boden and Wood Treatment Ltd. were also dropped, but both pleaded guilty to a health and safety offense, so proceedings continued until June 18, when Boden was given a nine-month prison sentence (suspended for 18 months), fined £12,000, and banned from being a company director for four years. The firm was fined £75,000.
The outcome was £75,000 in fines but no prison time.
The judge described Boden as a “totally inadequate managing director” and said that Wood Treatment Ltd. was “woefully wanting” in the discharge of its basic obligations. However, the criticism and the sentences were not enough for the victims’ families.
One of Dorothy Bailey’s sons, Matthew, said, “It’s been nearly six years. It’s every day you wake up and think about your parents and if this nightmare is ever going to end.”
His brother, Ed, said that Dorothy’s loss had left “a big hole in our lives” and called the sentencing “a joke” and “a kick in the teeth.”
One worker who had been employed at the mill for 39 years sympathized with the families. “We knew when the judge said there was no case to answer that today wouldn’t bring an end to it. It’s never going to end now for the victims,” he said.
Six years after the Bosley Mill explosion, families still grieve.
The dangerous conditions and the health and safety offence at the mill, were observed by employees and condemned by safety professionals, but nothing was done, even after at least one dust collector explosion occurred. Whether it was due to ignorance on the part of management, or lack of money, or both, four people went to work on the morning of July 17, 2015, fully expecting to go home to loved ones at the end of the day.
They didn’t.
Until the dangers of combustible dust are fully realized, more people are going to clock in, unaware that they’ll be working their final shift, with a health and safety offence at their facility. Any mistakes in health and safety offences need to be identified and addressed before they become tragedies.
Do you know of a combustible dust hazard that isn’t receiving the attention it deserves? Or an incident that hasn’t been reported in the media? Share your information anonymously at www.dustsafetyscience.com/dust-safety-share.
