One of Huddersfield’s biggest firms is writing to more people than ever before to let them know about its early warning system.

Syngenta, which has just spent £250,000 upgrading its warning siren, has written since 1985 to its neighbours – both residents and companies – warning them if it is testing its emergency sirens.

Now under new guidance from the Health and Safety Executive it is now having to write to more householders and firms across a wider area that stretches from Deighton to Dalton and from Woodhouse Hill to Kirkheaton.

The letters, which are arriving this week, give information about the manufacturing processes on the Syngenta site at Leeds Road and also what people should do if the siren sounds.

The siren will be tested in October.

Syngenta in Huddersfield makes products which help farmers worldwide protect crops from pests, weeds and disease and has been manufacturing for nearly 100 years.

Around 80% of its workforce live in the Kirklees area – 65% in Huddersfield.

Syngenta community relations manager Carl Sykes said: “For the last 28 years Syngenta has written annually to its neighbours, providing information about Syngenta, the materials used at the site and emergency response plans in place to safeguard people in the unlikely event of an incident. This usually takes place shortly before the annual siren test, as publicised in the Huddersfield Examiner.

“Last year, despite no change to the materials used and stored at the site and no change to its manufacturing processes, the Health and Safety Executive provided Syngenta in Huddersfield with new guidelines regarding its public information zone.

“As a result, the public information zone has increased by approximately 30% and from now will include up to 8,700 households and 300 businesses. It used to be around 4,800 houses and 200 businesses.

“Working closely with the emergency planning department of Kirklees Council, this has meant a new zone has been defined .”

He added: “There is no greater risk today than there was yesterday. As an operator, we are dutifully following the guidance we have been given by the HSE .

“Understandably, some residents and businesses who have not previously had a letter from Syngenta may have questions about why they are now receiving one and we shall do our part in helping to answer them.

“Syngenta has won industry awards for the standards of our process safety and we have sophisticated control systems which allow us to take preventative action before problems arise. We co-operate with all of our regulators and always work to the standards they set – and in many cases to a higher standard.”

Mr Sykes added: “Our goal is to continue doing our bit, providing skilled jobs, apprenticeships and trade.”

Huddersfield MP Barry Sheerman said people should not be concerned at all that more now have to be notified.

He said: “The company has an exceptional safety record and an excellent management structure. Some of this seems to be unnecessary red tape by the Health and Safety Executive.”