A small building company which accidentally caused an asbestos scare in a village school, leading to a £190,000 clean-up operation, has been fined £1,100.

Taunton Crown Court was told the incident led to asbestos being spread around Westonzoyland Primary School, but Somerset County Council's safety measures meant none of the 150 pupils were at risk.

Westonzoyland builder Dave Lee Ltd had won a £25,000 development contract under the supervision of the headmaster and school governors, and was told to carry on with the work during the summer holidays in 2007 after asbestos was discovered because it was deemed to be of low risk.

In summing up the case, Judge Graham Hume Jones said only the firm's two employees, who continue to work for the firm, were exposed to the risk. They were told to carry on "by others who should have known better", he said.

The work was beyond the company's experience and "in my judgement the risk was taken by those who advised the school and headmaster", said the judge.

He added that there was no question of the company cutting costs or failing to heed warnings, and that it had a good safety record and made a prompt admission of liability.

"It should be noted that the company has not been paid for the work done – £14,000, a sizeable sum for this small company," he said.

He went on to say that the firm should not have taken on work in which it was not sufficiently experienced and those in authority should have known that.

The firm pleaded guilty to failing to prevent employees being exposed to asbestos and failing to identify asbestos which, the judge said, could easily have been dealt with in a magistrates' court.

He said: "I am told the costs are £12,600.

"In my opinion this has been greatly inflated because I consider the responsibility for the danger has been passed down to the defendant."

The company was ordered to pay a £500 contribution to costs.

After the hearing Sue Adsett, an Inspector from the Health and Safety Executive who brought the prosecution, said: "Asbestos causes 4,000 deaths a year in this country.

"Small builders have got to learn about it and know when they have to stop work and call in licensed contractors to deal with the problem.

"People in charge of buildings also need to know if they contain asbestos, and make sure it is safely removed before refurbishment begins."