A SIREN warning system is to be installed at a chemical factory which had two toxic gas leaks last year.

Bosses at Nipa Laboratories in Oswaldtwistle, with help from Lancashire's emergency planning chiefs, tested an early warning klaxon system earlier this month.

Although it was heard by people as far away as Accrington, some residents in Oswaldtwistle claimed it was inaudible from inside their homes.

The siren will be activated if an accident at the plant in Nook Lane were to put residents in danger.

Nipa says it is satisfied that residents who are downwind from the site can hear the siren, and is hopes to have the alarm system installed by late February.

Some residents reported that the test alarm could be clearly heard when they were outside, but not when they were in their homes.

People living within a kilometre of the site will receive letters explaining what the klaxon does and when weekly tests of the siren will take place.

Glenys Jones, the company's health, safety and environmental manager, said: "We had people stationed around the area, both indoors and outside to report back on how well the klaxon could be heard.

"Our people reported positively, and out of 20 calls to the site, just one was unable to hear the klaxon. He was upwind, so the sound was being blown away from him."

A spokesman for the county council's emergency planning department said: "Overall, the results were good, with people downwind being able to hear the klaxon - and that is the important area.

"There is also the option to support the klaxon warning with loudspeaker and radio announcements."

Nipa publicly apologised to local residents following a gas leak in May, and the company is awaiting sentence at Burnley Crown Court after it admitted six offences under the Environmental Protection Act following the incident.

A second, smaller accident last November is also being investigated by the Environment Agency.

Converted for the new archive on 14 July 2000. Some images and formatting may have been lost in the conversion.