Toxic fumes from a potentially lethal chemical solvent closed the majority of the main Washington Mall shopping complex yesterday with some shoppers and shop assistants being physically sick due to exposure to the fumes.

Contractors removing carpet from an empty store on the mezzanine level were using a hazardous xylene solvent to dissolve glue on the floor left behind by the carpet. But the toxic fumes soon permeated throughout the interior of the mall.

There was confusion during the morning as owners of some shops and a cafe decided to close rather than wait for an official decision.

By late morning office health department officials and the Fire Service ordered the affected areas of the shopping mall be evacuated and closed in the interests of public health.

Shopkeepers quickly locked up their premises and left, while the main indoor mall was plunged into darkness with the lights switched off and industrial fans brought in to expel the fumes.

Washington Mall general manager Paul Savage said: ?Contractors who were removing carpet from a vacant shop ? who were not employed by us ? were using a solvent called xylene.

?When the canister they were using was retrieved it had all been used. The canister was given to the health department.?

Xylene occurs naturally in petroleum and coal tar and is one of the top 30 chemicals produced in the US. It is known to cause irritation to skin, eyes, nose, throat and create breathing difficulties depending on the level of exposure, while high exposure has been known to cause death.

There is a latent danger from the chemical solvent when used in enclosed, confined spaces. Shop-fitting contractors had begun using the product at the start of the day in the former Sound Stage shop at the top of the escalator.

By the time many of the shops opened for business the fumes were already causing concern and had spread through the internal ventilation system into various shops.

One of the first to decide to close was Johnny Troja, owner of the Delicious cafe and deli on the ground floor. Food that had been prepared for breakfast-time customers was thrown away because it had been tainted by the smell of the fumes.

Speaking mid-morning, before the order was given to evacuate the affected section of the mall, he said: ?We don?t know what is going on. We heard that someone has used some kind of stripper. We are taking no chances. We are throwing away most of the breakfast food and will be closed for the day.?

Neighbouring shops also closed and put up notices to inform customers. Ellen Brown, of The Body Shop, closed her shop as staff complained of feeling slightly nauseous.

Upstairs on the mezzanine level next to the shop unit where the chemical solvent had been used, Annmarie Clark closed her shop Magic Moments as the Washington Mall management send out the message for the area to be evacuated.

She said: ?The health department people said earlier that we should close if we start to feel light-headed. When I first opened in the morning I thought the smell might have been coming from the hairdressers. I know some people have been vomiting.

?I?ve lost eight customers already today. Mothers usually come in with their babies but they don?t want to take the chance. I don?t want to close my shop on a Monday because it is a big day for me.?

Sheri Lema, of Dodd?s hairdressing salon, said: ?It hasn?t been as bad in here as we have two doors. I have a little dull headache though. Rather than have anyone become sick they want us to close up. We are going to lose business but it?s a gift of a day off.?

The fumes affected only the ?phase one? area of Washington Mall, said Mr. Slaughter, with some business in Washington Lane also closing for the day.

He said it was intended to keep the closed areas off limits for the remainder of Monday and the mall?s air ventilation system was being opened up completely to the outside to help disperse the fumes. ?This is the first time we have had anything like this happen,? said Mr. Slaughter. ?This kind of work should have been done during closed hours, at the weekend or in the evening, and that is what we would have insisted upon if we had been advised in advance.?

Mr. Slaughter said the Washington Mall management would be speaking with the contractors involved in the incident.

An investigation is now being conducted by the Occupational Safety and Health Office into what chemicals and substances were being used, how they were being used, and how the incident occurred.

Doris Foley, senior safety and health officer, said: ?We are gathering all the statements to determine the cause and whether the chemical was being used as directed by the manufacturer.?

The result of the investigation will not be made public.