Thursday, April 13, 2006

Benzene in soft drinks story heats up

A cold drink tastes good on a hot day but it might not be so good for you. The rediscovery (see here and here) that the known human carcinogen benzene can be produced in the many soft drinks containing the preservative sodium benzoate and ascorbic acid (Vitamin C) has refocused attention on a problem known to some manufacturers and the FDA for over 15 years. The ascorbic acid can be added and appear on the label or be part of added natural juice.

Regulators in the US and the UK have confirmed that numerous soft drinks exceed the UK (1 part per billion, ppb), US (5 ppb) and WHO (10 ppb) standards for benzene in drinking water. While there are no standards for benzene in soft drinks, in the UK they found 38 exceedances of their drinking water standards in soft drinks and have shown there is potential for even higher levels in these products:
One scientist who helped the soft drinks industry sort out the same problem in 1990, however, said testing drinks after exposure to heat and light was now crucial.

“When those 38 drinks that [the UK Food Standards Agency] tested positive for benzene are subjected to even short periods of heat and light, they could dramatically increase to beyond the WHO 10 parts per billion water standard.”


Britain's Food Standards Agency has not tested soft drinks for benzene after heat exposure; although a European Commission spokesperson said new guidelines on benzene testing, now being drawn up by the soft drinks industry, were likely to include “predictive testing to simulate storage”.

Industry testing on soft drinks 15 years ago is thought to have found that temperatures of 30°C and exposure to UV light for several hours were enough to more than triple benzene residues in some drinks. (Food Navigator - USA)
It is not uncommon for drinks to be subject to high heat in warehouses or in the trunks of cars in direct sunlight during summer months. I'm guessing with continued publicity it won't be long before sodium benzoate and ascorbic acid won't be in the same drink:
“What are we to tell consumers? ‘Product contains cancer-causing substance, drink immediately, do not store in a warm environment or near sunlight?' Preferably benzoate should not be used in combination with vitamin C (ascorbic acid) or added juice,” said the scientist involved in industry testing for benzene 15 years ago.
Now that would be an informative label.