THE Health and Safety Executive confirmed last night that it had already ordered a tightening-up of safety procedures at the Distillex plant following a previous toxic leak.

The leak, in January, caused dozens of people to feel unwell after inhaling methylene chloride, which escaped in a cloud.

Homes were evacuated and pupils sent home from schools, while police set up roadblocks in case the fumes were carried in the wind.

The cause was found to be a cylinder in the distillation section of the plant, which had overheated and released gas used in adhesives and paint strippers.

Last night, a spokesman for the executive said a thorough investigation into the incident was still being carried out.

It was not linked to last night's fire, which was in a separate part of the North Shields plant.

Distillex had been asked to meet a number of conditions to try to prevent a repeat of the toxic leak.

These included a suitable risk assessment for the processing of the material involved in the leak.

The spokesman said: "To the best of our knowledge, the conditions imposed have been complied with."

The executive said it was now investigating the latest incident at Distillex in conjunction with the Environment Agency, which was taking the lead.

A spokeswoman for the agency said it had a number of officers at control points near to the site of the fire, who were providing advice to the fire and emergency services.

It was too early to say whether any enforcement action would be taken against Distillex.

The company, which employs 44 staff, produces solvents for domestic use and for export to metal, plastic and other processing industries.

It has two manufacturing sites in the UK, at North Shields, on Tyneside, and in Leyland, Lancashire.

The firm's latest accounts show a turnover of £3.1m for the financial year ending March 31, 2001.