Store withdraws peanut butter

Some peanut butters contained a high level of aflatoxins

A supermarket chain has removed a batch of own-brand peanut butter, after cancer-causing chemicals were found in a pot.

The move comes after scientific studies showed that some peanut butter on sale in the UK contained excessive levels of naturally occurring contaminants called aflatoxins.

A study by the BBC 10 O'Clock News found excessive levels in one pot of Tesco peanut butter.

Tesco's own tests found no trace of the substance, but it has withdrawn all jars from the same batch as the affected one.

Peanut samples are routinely tested by scientists

Health officials have called for tighter controls on products.

British consumers spend nearly £30m a year buying the product - despite concerns about the increasing number of peanut allergies.

In an exclusive study commissioned by the BBC, one product from Tesco had more than twice the maximum level of aflatoxins permitted under EU safety rules.

Trading standards officers say the current controls are not sufficient to safeguard against contaminated nuts entering the UK and urgent action is needed.

The problem occurs when peanuts are contaminated by a fungus that produces toxins linked to liver cancer.

But the fungus occurs haphazardly, so one jar of peanut butter may have high levels, while another from the same batch may not.

Exclusive findings

Public health analyst Peter Brown said it had been "a particularly busy season" for peanut imports found to be affected.

In the past year, port health officers in Felixstowe taking peanut samples say they have condemned 30 out of 250 consignments.

A further 40 were deemed unfit for human consumption without further processing.

In a report disclosed exclusively to the BBC, Suffolk Trading Standards found that five out of 20 samples of peanut butter tested contained excessive levels of aflatoxins.

The BBC then conducted another study, sending 17 different types of peanut butter to the public analyst.

Fourteen contained aflatoxins - though most within the legal limit of two micrograms per kilogram.

The public has the right to know that limits have not been exceeded

Institute of Cancer Research

When tested, some jars of Tesco's 25 per cent less fat smooth peanut had an unacceptable 4.2 micrograms per kilogram.

A spokesman said: "We do not dispute that researchers found one jar contained aflatoxin as it would only take one peanut to contaminate a pot.

"However, the whole nature of processing means this would not necessarily contaminate a whole batch."

He added that most jars in the affected batch would have already been bought as they went into stores in May.

Any customers who were concerned could bring their jars back to the store and get a full refund, said the spokesman.

He said eradicating aflatoxins was a challenge facing the whole industry.

Professor David Phillips from the Institute of Cancer Research said the level of chemicals being talked about posed only "the tiniest risk" to health.

But he added: "The public has the right to know that limits have not been exceeded.

And any product that has exceeded the limit should probably be taken off the market".