Faulty aerosol can may have caused builder’s death

By JOHN ROBERTSON

AN AEROSOL can of expanding foam which exploded and killed a young Brae man could have been faulty, a fatal accident inquiry heard in Lerwick this week.

It was widely assumed after James Thomson’s death in March last year that he had overheated the Evo-Stik Foam Filler using a fan heater, or even a blowtorch, but information now coming to light has raised questions about the safety of the canisters, man­ufactured in Switzerland by Polypag AG for Bostik, owners of the Evo-Stik brand.

The concern has been magnified by news of four other explosions involving expanding foam cans, including two in Shetland. The others were in the Czech Republic and Denmark in 2004 and involved Polypag cans. Bostik said it was only told about them last week.

On Tuesday, after two days of evidence at the inquiry in Lerwick Sheriff Court, it was clear crucial questions about the tinplate cans were not being answered authoritatively by Bostik’s quality manager from England, Kenneth Hanlon, who could only repeat in his testimony information he had been given by Polypag.

Sheriff Graeme Napier decided he had little option but to adjourn the inquiry so Polypag can be invited to attend and bring its lawyers. He said it would be “a travesty of justice” to allow matters to proceed without the approach being made. Scottish courts have no legal powers to compel attend­ance by people or companies from outwith Scotland. The inquiry will reconvene briefly on 8th September to hear Polypag’s response before setting a date for proceedings to resume.

Before it was halted the inquiry had fixed its focus on the man­ufacture and testing procedures for the cans and whether faults can develop either from the way the metal is put together or from water contaminating the foam chemicals, causing extra pressure to build up.

If sheriff Napier eventually finds fault with Polypag’s man­ufacturing process or Bostik’s role in selling the goods it could have worldwide implications for aerosol products of all kinds.

It emerged during evidence that Bostik had been quick to assume that Mr Thomson was at fault for the accident by not following the instructions for the product and it therefore did not order independent safety checks or change the warnings on the label changed. In fact, after hearing of the accident it sent an area sales manager to Shetland, not to talk to officials, but to sound out rumours to add to the reports the company had gleaned from the media.

Mr Thomson’s widow, Karen Thomson, sat through the two days of evidence from the first six witnesses. Afterwards she said she was disappointed the inquiry could not be concluded this week but her priority is and always has been to get to the bottom of what caused her husband’s accident so that no other family has to suffer in the same way.

The sheriff extended the court’s condolences to her and the rest of the family on Monday after details of the tragic accident had been recalled in detail during the day. The inquiry heard that Mr Thomson, 26, could not have survived the injuries suffered when the can of Evo-Stick expanding foam exploded in his hand, hitting him between the chest and abdomen. He was working for his father’s company Dennis Thomson Builders Ltd on a new house in Levenwick when the accident happened on the morning of Saturday 10th March 2007.

What is not disputed is that he had a number of cans of the polyurethane foam lined up in a room to warm in front of a tiny floor-level fan heater before he used them to block drafts around the edges of window frames in the house.

According to Bostik’s product data sheet, the Foam Filler works best at 20° celsius and it advises that very cold cans should never be warmed up quickly. The con­tractor’s supply of 36 cans was kept stored with other materials in a steel container outside and it is not thought that central heating was on in the house, although it had been connected.

The 500ml cans were out of date by two months but the inquiry heard evidence that, according to Bostik, the product becomes less efficient to use beyond the date, not less stable or safe.

Mr Thomson’s fellow worker that day, Jim Sandison, told police he had been working in the bathroom when he heard a bang and a shout for help. He raised the alarm and tried to resuscitate his workmate before an ambulance crew arrived but Mr Thomson died where he lay. An autopsy revealed a ruptured heart and damage to other internal organs from the explosive force of the canister, even though the only external mark was a dark oval-shaped ring on his skin.

The pathologist in Aberdeen, Dr James Grieve, told the inquiry the effect of such force on the heart and internal organs was “certainly unsurvivable” even if hospital treatment had been on hand immediately. “Nobody could have repaired the damage in sufficient time for him to survive,” he said.

Examining the bits of the can in court, he could not be sure which part hit Mr Thomson but reasoned it was most likely the bottom end, which was slightly crumpled. The top end blew off. The room in the house was covered in flecks of plastic foam.

Mr Thomson’s father, 58-year-old Dennis Thomson, said his son was a qualified joiner who had been about seven years with the family firm, which builds private houses, agricultural buildings and some commercial projects. The house at Upperton in Levenwick had been structurally complete at the time with the linings, insulation and internal partitions up and work starting on the trim.

When he visited the house the previous day at 5pm neither the heater nor the cans were in the position found after the accident. He said he put the fan heater to the house about a month before to circulate air so that a humidifier worked more efficiently.

His company had used expanding foam for about 20 years without accident although prob­lems were experienced getting around 20 per cent of cans to operate properly if used at outside temperatures. It was preferred to have the cans inside at room temperature but it was not always possible, he said.

When it was suggested that using a bucket of warm water was common practice, Mr Thomson said his company had never done that. “We didn’t have a policy for warming them up – we accepted the failure rate.” Asked if he accepted that the fan heater had been used to heat the tins, he said the evidence suggested it was possible. “At that point in time I would not have been alarmed if I had seen that.”

Despite the rumours in Shetland at the time, he said no gas blowlamp had been used and the only one the company had was 40 miles away at the time.

He concluded: “I don’t think we did anything wrong or I don’t think he did anything wrong either.”

Procurator fiscal Duncan MacKenzie said Mr Thomson trusted his employees to read the instructions on the labels of products and tools they use. Since the accident he said Mr Thomson had compared many labels on pressurised cans, from hairspray to cream and including paint and lubricants and they were no different to the foam filler in stating that they should not be exposed to heat over 50° celsius.

The third witness on Monday, detective sergeant Lindsay Tulloch of Shetland police, had been called to the scene after the accident happened. He took away 15 cans of Evo-Stick foam and the fan heater, which had been set on maximum temperature and output, although he found it was switched off at the wall. The equipment was sent to the Health and Safety Executive (HSE) in Buxton, England for investigation. His conclusion was that Mr Thomson had been heating the cans in front of the heater and one had exploded after being picked up.

Some doubt has been expressed in the inquiry that the fan heater could put out enough heat to cause an aerosol to burst. However, evidence to support that theory has not so far been presented.

The final witness on Monday was Gordon Laurenson of the Lerwick company Herculean, which sells a wide range of goods including chemicals and expanding foam. He told the inquiry about an explosion involving a different brand of foam, Everbuild, some months before Mr Thomson’s accident. One weekend after the shop was closed a canister had gone off in the store due to being close to a corrugated iron wall which heats up in the sun. Nobody was there at the time.

On Tuesday an HSE inspector from Edinburgh, William Todd, who investigated the Levenwick accident, said he had no concerns about the safety procedures of Dennis Thomson Builders. He said the agency had not been alerted to incidents of exploding cans prior to Mr Thomson’s death. However Dennis Thomson had told him of six examples involving the foam that he had learnt about. But when Mr Todd checked out four of them, two of the people mentioned said they could not recall such incidents. Apart from Mr Laurenson the other confirmed case involved a Mr Burns who had been working in Shetland 10 years previously. He had taken a can from a pack in his van and was climbing a ladder when it exploded. He was not hurt.

The final witness, Mr Hanlon from Bostik’s base in Stafford, was on the stand the longest and endured the toughest questioning. He told how Polypag AG had supplied Bostik for at least 10 years. It makes and cans the formulation B3 foam for many companies in Europe who get their own brand names on the tin.

Bostik does not carry out its own safety checks, relying instead on Polypag’s quality assurance system and assessment by Bureau Veritas, the European equivalent of the British Standards Institute. Mr Hanlon said Polypag’s system includes vacuum-testing of every can before it is filled and pressure-testing of one every hour from the filling line. If a can fails the pressure test, 10 more are tested. If any of those also fail then the batch is rejected.

However, Mr Hanlon did not know whether the pressure-tested cans contained water or the foam polymer product and he was unable to answer detailed questions on the testing process from the sheriff, procurator fiscal Duncan Mac­Kenzie and solicitors Lisa Gregory for Mrs Thomson and Chris Dowle for Dennis Thomson. They were trying to establish a number of facts including whether tested cans are put back on the production line, whether water might have got into some and how often cans fail the tests.

Solicitor Linda Knarston, appearing for Bostik, was able to tell the inquiry that in tests the cans usually burst under pressure of 20.6 bars. They are rated to 18 bars.

When Bostik heard of Mr Thomson’s death it held a meeting immediately to decide whether or not to continue selling the product, Mr Hanlon said. It decided to continue; to inform the supplier about what had happened and to seek information as to whether there had been similar incidents.

He said Polypag had reported no injuries from use of the product but, pressed on whether it reported any explosions, he said there had been two incidents in Europe but both had been after a can was subjected to “extreme temp­eratures”. He said he had no further information on these cases except that they had happened in 2004.

Pressed further, he revealed that Polypag had only seen fit to inform Bostik about those explosions last week, which he agreed was disappointing. He had not seen any report from any Polypag inquiries into the Thomson tragedy, nor had Bostik sought one from the company. “We sought confirmation that the product was safe to sell,” he said.

Asked if Bostik and/or Polypag had formulated a reason for the can failing so dramatically in Shetland, he said: “The use of heat in this incident must be a contributory factor.” He said it was stated on the cans that they should not be exposed to heat over 50°C. A product data sheet, which is not provided with the cans, states that the foam should not be applied when below 5°C or above 25°C.

Sheriff Napier asked why Bostik was still content that it was supplying a safe product when it did not have full information about the other accidents. He accused Bostik of adopting a “laid-back” attitude by deciding to take a risk instead of stopping the product. Mr Hanlon replied that further information was being asked of Polypag, which he said had investigated the 2004 incidents, but it had assured Bostik the product was safe to supply.

Mr Dowle suggested Bostik might want to revisit its labelling to provide clearer warnings about use of the foam cans. He said he could not understand how a company could continue to supply a product when it did not know the temperature the various failed cans had been subjected to.

Under a barrage of further questioning from Mr Dowle, Mr Hanlon admitted Bostik had not asked for independent tests despite having learnt of three explosions involving Polypag foam cans, nor had it again reviewed its continued sale of the product. Bostik had also so far failed to inform the HSE about the two explosions in 2004 even though it knew the agency had been investigating the safety of foam cans. Mr MacKenzie said if the HSE had known of the incidents they could have liaised with their foreign counterparts and the inquiry would have been in a position of enhanced knowledge.

Asked whether Polypag’s failure to keep Bostik informed would cause Bostik to now review the relationship, Mr Hanlon said: “It’s not for me to say but it will not go unmentioned.”

Although no detail was given, sheriff Napier said there was evidence to show that water might have got into some cans. The inquiry heard if that did happen the foam could begin reacting or “curing”, giving off carbon dioxide, leading to an increase in pressure and the danger of it bursting.

The sheriff then called the legal teams to his private chambers where they discussed progress for nearly an hour. Emerging to address the court, he said all parties were resigned to the fact that Polypag needed to be contacted in order that as much as possible could be established about the circumstances of James Thomson’s death.