A defence company's slack health and safety regime led to the death of a worker who was blown up by a build-up of volatile nitroglycerin, a court heard today.

Wallop Defence Systems Ltd (WDS) exposed technician Anthony Sheridan to the highly explosive substance as he emptied an oven containing flare pellets at the firm's factory in Over Wallop, Hampshire, in June 2006.

The 37-year-old was blown 29 metres from the explosion that sprinkled debris more than 300 metres, Winchester Crown Court heard.

The company was making the decoy flares for the Ministry of Defence and they were used to protect aircraft, but it had been known since 2004 that the pellet curing process inside low temperature ovens made nitroglycerin as a by-product.

Measures were taken to try to deal with the potential hazard that the company recognised in a report in 2004 was a ''serious explosive risk'', Mark Harris, prosecuting told the court.

WDS set up a cleaning process to help with the problem but failed to carry out a series of risk assessments to highlight any danger.

Bins to hold the nitroglycerin were not emptied for a year and left outside in cold weather, which could have triggered an explosion as the substance crystallised, the court heard.

Mr Harris said that the company had made ''misjudgments'' rather than ''intentional acts''.

''There was no conscious decision to take a shortcut for commercial gain, but the pressure to increase production caused the management to be highly negligent in addressing the risks at the time.''

He explained that the company had not addressed the fundamental problem of nitroglycerin being a by-product and that it would continue to be a hazard. It also didn't have a licence to store such a hazard.

''There was a singular failure to understand the nature of what was being dealt with,'' the barrister added.

The Ministry of Defence asked the company to hand over its design for the flares to another company who had managed to cure the pellets and not produce nitroglycerin, the court heard.

After the fatal explosion, the company brought in an outside expert from Cranfield University but he was ''not competent'' to deal with issue and was not an expert in nitroglycerin, Mr Harris said.

The Health and Safety Executive were not asked for their advice and when the company went to dismantle an oven and drilled a rivet out it led to a fire and another explosion where no-one was hurt because the site had been evacuated in time.

WDS pleaded guilty at a previous court hearing to breaching Section 2 and Section 3 of the Health and Safety at Work Act from 2004 to 2006 in connection to the death, and to a further Section 2 breach for the second explosion.

It admitted it had failed in its duty to ensure the health, safety and welfare of Mr Sheridan, who was from Over Wallop, and other workers.

Judge Guy Boney QC indicated he will sentence the company on November 9.