Science lab demonstration to highlight danger of smoking banned in schools

The move has been derided as "ludicrous" by opposition MPs, who argued that the experiment was safe if conducted in a school science laboratory.

About 300 out of Scotland's 400 or so secondary schools have in the past used the simple device, which consists of a fitted pipe and a lit cigarette.

The Department of Health in England will permit the experiment when its smoking legislation is enacted this summer.

However, teachers north of the Border could face prosecution if they use the mechanism with a lit cigarette inside the classroom to demonstrate the impact of smoking.

Instead, they have been told they must have a properly designated "smoking" laboratory room designated specifically for the experiment or conduct the test outdoors.

The ruling has baffled an advisory body, the Scottish Schools Equipment Research Centre, which argued that conducting the smoking machine test outside could actually be more dangerous to pupils' health if smoke was blown their way on a windy day.

Ministers in Scotland are now facing calls to amend the Smoking, Health and Social Care (Scotland) Act 2005 to exempt smoking machines.

Willie Rennie, the Liberal Democrat MP for Dunfermline and West Fife, said he had fielded complaints from science teachers who were keen to show the impact of smoking on the lungs.

Mr Rennie said: "I am alarmed that the Scottish Executive is interpreting the legislation in this way.

" This experiment is a valuable tool in the campaign to persuade people not to smoke."

Jim Docherty, the depute general secretary of the Scottish Secondary Teachers' Association, said the authorities had to make it "abundantly clear" to teachers that they could face prosecution if they failed to comply with the new law. "If someone were to conduct the experiment, I don't think that prosecution would be an appropriate measure. I would hope any teacher would know they could not carry it out inside," he said.

Kenneth Robertson, the secretary of the education division of the Royal Society of Chemistry, and head of science at a Glasgow school, said: "Now the dangers of smoking have to be conveyed via a video which just doesn't have the same impact."

A Scottish Executive spokeswoman said:

"Schools have to ensure that smoking experiments conducted inside school premises can fit with this specific exemption otherwise the practice would be a violation of the law."

• SUPERMODEL Kate Moss was attacked by MSPs yesterday for setting a bad example by smoking.

Andy Kerr, the health minister, said he believed that paparazzi pictures of the celebrity with a cigarette in her hand were a factor in encouraging young women to take up the habit. "It's age-old evidence in relation to how people view pop stars, rock stars and actors," Mr Kerr told Holyrood's health committee.

"And, yes, I would want people to look at their behaviour and ensure that they're not setting what is a very dangerous example for young people."

He said celebrities such as Moss should not be "so blas" about smoking in public, adding: "I would ask her to refrain in terms of public smoking and understand the impact she's having on young people's lives."

A quarter of 15-year-old girls in Scotland are regular smokers.

The committee yesterday discussed the impact of Scotland's public smoking ban.MSPs were told it has led to a 86 per cent drop in exposure to second-hand smoke for bar workers.