London firms set up 'clean rooms'

Around 20 London firms have set up special sealed-off zones in their offices to protect staff in the event of an anthrax alert, it was claimed today.

Two firms which normally specialise in asbestos clear-up operations say they have been hired by anxious employers to establish the zones, known as "clean rooms".

A clean room is an enclosed space in which any doors and windows can be easily blocked. It is equipped with a machine which blows in filtered air.

Workers would effectively hide out until the authorities complete a decontamination operation.