NATIONAL Semiconductor"s Greenock plant was at the centre of a full-scale alert yesterday amid fears that three workers had been contaminated in a chemical spill.

Fire crews, ambulances, police and a specialist paramedic decontamination unit rushed to the factory after a woman working in the 'wet deck' area fainted and two other members of staff - a man and a woman - complained of feeling unwell.

The emergency services, called by the ambulance crews when it was revealed the workers had been near potentially dangerous materials, sent three fire engines and a unit of officers trained to deal with chemical alerts. Wearing rubber suits that protect them from hazardous materials, the firemen checked the area where the woman had been working. Police cordoned off a large area of the plant"s grounds for most of the morning.

The decontamination unit was set up outside by specialist ambulance crews to treat the three workers.

It was made up of two tents which housed portable water sprays and powerful detergent to clean the workers.

While Strathclyde Fire Brigade"s Technical Support Unit checked the plant for any possible chemical or radioactive contamination, the three people were taken to a medical area where they were checked by first aid personnel.

They were then strapped to trolleys and wheeled to the decontamination tents.

Inside, they were stripped by paramedics wearing full environmental protection suits and scrubbed with warm water and detergent.

Their clothes, which could also have been contaminated with lethal substances, were separated into plastic bags outside.

After the decontamination process was complete they were escorted into ambulances, attached to the unit by a long tarpaulin, and rushed to hospital. Two of those taken to hospital were allowed home yesterday.