Coca Cola Schweppes and Boots the Chemist began sweeping thousands of bottles of potentially contaminated mineral water off shop shelves yesterday as a major scare swept through the soft drinks industry.

All bottles of sparkling Malvern water were being pulled after traces of the cancer-causing poison benzene were found in carbon dioxide supplies used to make the drinks.

Another water, Brecon Carreg, was also being taken off the shelves and other companies were poised to take similar action if tests on their products proved positive.

The contamination has been linked to carbon dioxide made by a West Country factory and distributed to a number of companies.

Coca Cola Schweppes said it was taking action after establishing that the suspect CO2 had been used in its Malvern Water factory.

The company said it was also freezing stocks at some of its secondary factories until full analysis had been undertaken.

A spokeswoman said the problem had only affected a small proportion of its total output but she said they were taking the action ''as a responsible manufacturer''.

Brecon Carreg is sold both as an individual brand and as an own label water in stores including Boots, Tesco, Safeway and Waitrose.

It was pulled after tests also proved positive.

In both cases it is only sparkling water that is affected.

The scare was sparked on Friday after some samples of water were found to contain up to 20 parts of benzene in one million, twice the World Health Organisation guidelines.

Experts stressed there was virtually no health risk attached to drinking the polluted drink but companies said they were taking the issue seriously in the interests of customer confidence.

A spokeswoman for the Ministry of Agriculture, Fisheries and Food said: ''The amount of benzene you absorb from traffic fumes is about the equivalent of drinking 40 litres of the most contaminated of these drinks.

''You'd soak up more benzene walking to the shop to buy a can than from drinking it. It's a matter of quality, not safety.''

Drinks should contain zero amounts of benzene.

An industry insider said the scare had sparked pandemonium as firms rushed to see whether their products were affected.

She said: ''Everyone is wanting to test their products. The laboratories are working flat out but some firms have had to send samples to Europe to get them analysed.

''So far it's only been sparkling mineral waters that have been affected, but results are coming in all the time and other companies may have to take action. Even though there's no health risk, nobody wants to have benzene in their drinks - particularly mineral water which has a healthy image.''

In 1990 Perrier withdrew 160 million bottles of its water after experts in America found traces of benzene at up to 22 parts per billion in 13 bottles.

Bob Snowdon, spokesman for Terra Nitrogen (UK) Ltd, the company near Bristol which produced the carbon dioxide at the centre of the scare, insisted there was no threat to the public.

''We don't believe it's a dangerous level. All the information we have suggests it's a quality issue, and there's very little risk associated with the levels found so far,'' Mr Snowdon said.

Rob Hayward, director general of the British Soft Drinks Association, also insisted that the only concern was about the quality of products.

''We are absolutely determined to ensure that all product is perfect and notification of any level above the figure of 10 (parts of benzene per billion) will result in product recall,'' said Mr Hayward.

Britvic Soft Drinks later said it was withdrawing 2,250,000 cans of drinks which it believed were affected. These included 330ml cans of Regular and Diet Orange Tango, Regular Lemon Tango, Pepsi Max, Diet Pepsi, Regular 7UP and 7UP Light.

A spokeswoman said specific batches of drinks had been identified as potential problems and these were being targeted in the recall rather than all cans being pulled off the shelves.

''It might sound a lot of cans, but it's actually only a small part of our production,'' she said.

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