THE inspector whose unheeded warning could have averted the Stockline factory disaster has criticised the UK's workplace safety watchdog for its "slack" response to the tragedy.

Alan Tyldesley criticised his former bosses at the Health and Safety Executive (HSE) after they announced a UK-wide plan to replace the kind of gas pipes which caused the Stockline explosion. However, the HSE has set a target of 2015 - 11 years after the tragedy - to fix gas pipes across the country.

Nine people were killed and 45 injured when the ICL/Stockline Plastics factory in Maryhill, Glasgow, collapsed on May 11, 2004, after liquid petroleum gas (LPG), which had leaked from a 35-year-old metal pipe, ignited.

The cause of the blast has been known since 2007, when the firms responsible were fined £400,000 for health and safety breaches.

Last month, a public inquiry under Lord Gill said the tragedy had been "avoidable" and that replacing similar pipes was an "urgent priority".

The HSE announced last week that the estimated 15,000 to 40,000 UK businesses with buried metal LPG pipes would be made to replace them with polyethylene ones.

The HSE also said it wanted the 24,000 to 54,000 households with metal pipes to do likewise, but could not force them without a change in the law.

Tyldesley, who is now a private safety consultant, said the HSE response was too little, too late.

"HSE has spent five years getting to the point where they now think they can prioritise these things and, frankly, if they had spent the first couple training people up to put new pipework in we could be three years further down the line," he said.

He said there had been a "lack of drive" at the HSE since a reorganisation in 2004.

"I definitely think the timeframe is slack. It's an example of how they lost any sense of urgency or any sense of importance of this."

He also said the HSE didn't want to tackle LPG pipes in domestic properties "because they don't want the work that would go with it".

Lord Gill found HSE inspectors showed "inadequate appreciation of the risks associated with buried LPG pipework ... and a failure properly to carry out check visits".

But he praised Tyldesley, who recommended in 1988 that the pipe should be excavated and checked - something that was never carried out after the HSE agreed to a weaker compromise.

"Mr Tyldesley deserves great credit for being the only person in this history who was alert to the risk arising from the unknown condition of the buried pipework," Lord Gill wrote.

The compromise that did not involve digging up the pipe "was the critical event" for the HSE, he added.

HSE chief executive Geoffrey Podger said not taking Tyldesley's advice had been "pretty tragic", but dismissed his fresh criticism.

"He's entitled to his view but he is a retired member of our staff," he said.

"The generality of problems associated with this LPG has not been that great. It is important to make progress, but ... in a measured way."

But Maryhill MSP Patricia Ferguson said: "Everyone has known for years what the cause of the Stockline explosion was, but now HSE have set a timescale of fixing pipes more than 10 years after it."