CASTLE Cement has launched a legal challenge in an attempt to relax the tight controls on the burning of controversial Cemfuel.

Bosses at the firm's Ribblesdale works, Clitheroe, are to seek a judicial review to try to change the legal status of the fuel, made from recycled chemical waste, after claiming its classification by the Environment Agency had affected its business and the environment.

The decision to class Cemfuel as a hazardous waste meant the firm has had to stop burning it until new monitoring equipment is installed.

New European Community rules which came into force in June force firms which burn such waste to carry out much stricter monitoring of fume emissions.

Castle maintain that Cemfuel is a fuel rather than a hazardous waste and are hoping to put their case to a High Court judge.

"The decision of the Environment Agency to apply the terms of the directive to our operations had serious implications not just for our business but for the local and national environment," said production director Peter Weller.

"We are seeking a judicial review of the issue so that once and for all there is no doubt as to which regulatory regime applies to our cement works."

When the new directive was introduced in June, Castle did not have necessary monitoring equipment on its wet kilns number five and six, and stopped burning Cemfuel. The equipment has been installed on another kiln, kiln seven, for which the firm is now applying for permission to burn Cemfuel.

A spokesman for the Environment Agency said if Castle was given leave for a judicial review -- carried out by a high court judge asked to review a decision made by a court or statutory body -- they would co-operate fully with the legal process.

David Mortimer, chairman of Blackburn, Hyndburn and Ribble Valley Friends of the Earth, said a reclassification of Cemfuel would be bad news particularly in the light of a judge's comments in the recent court case against Castle.

Castle were fined £45,000 with costs for pollution offences after a case during which the judge said he doubted whether there was more Castle could do to prevent plume grounding -- when emissions from a chimney drift back to ground level.

"This is a valley which is incapable of dispersing emissions and where Lancaster Crown Court established that nothing can be done to prevent plume grounding or predict when it will occur."

When Castle Cement applied for permission to re-start the burning of Cemfuel, it said its own eight-month trials of Cemfuel had shown that it was environmentally beneficial.

It said that the dry kiln, kiln seven, operated well within the government limits when burning coal and when Cemfuel was introduced as a partial substitute for coal, environmental performance was improved.