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Sodium benzoate

In 2006 the Food Standards Agency (FSA) published the results of a survey measuring the levels of benzene in 150 soft drinks on sale in the UK. This was in response to allegedly dangerous levels of carcinogenic benzene in soft drinks as a result of sodium benzoate interacting with ascorbic acid (vitamin C). In more than two thirds of the samples tested the levels of benzene were undetectable, while 38 samples had levels between 1 and 10 ppb (parts per billion). The guideline level set by the World Health Organisation (WHO) for water is 10 parts per billion (ppb). 1 ppb is 1 part per billion, i.e. 1/1,000,000,000, which is equivalent to 1 microgram per kilogram (1ug/kg).

In May 2007 The Independent ran a story that sodium benzoate, a common preservative in soft drinks, damages the mitochondria in cells. Sodium benzoate (E211) is used in carbonated drinks to prevent mould growth. The article was headlined “Caution: Some soft drinks may seriously harm your health”. 


You can read The Independent article here



Here, Professor Sir Colin Berry, Emeritus Professor of Pathology responds:

Sodium benzoate is found naturally in cranberries, prunes, greengages, cinnamon, ripe cloves, and apples.  Its concentration when used as a preservative is limited by the FDA in the U.S. to 0.1% by weight in drinks but it is interesting to note that organically-grown cranberries and prunes can contain levels exceeding this limit. The International Programme on Chemical Safety found no adverse effects in humans at doses of 647-825 mg/kg of body weight per day so the safety margin is vast.

Benzene is ubiquitous in the environment and is found in “mid-Pacific-ocean air” at around 10ppt, in “background air” at around 2-10 ppb (USA data) and in the interior of a car will reach around 10-20ppb. When you fill the car with petrol the air will contain around 0.1-1ppm. Around 500ug of benzene is produced from an “average” cigarette and smokers have benzene in their breath.



Here, Professor Andrew Cockburn, Toxicologist, responds:

The approved food additives ascorbic acid (Vitamin C) and sodium benzoate can react to produce low levels of benzene when they are present in the same beverage. Exposure to low levels of benzene in industry over an extended period has been linked to the development of aplastic anaemia, which can lead to leukaemia.

The World Health Organisation (WHO) has set the acceptable level of benzene in drinking water at 10 parts per billion (ppb). In early 2006, tests performed on beverages in the USA found levels 2-5 times above this, sparking international concern. In response to this FSANZ (Food Standards Australia New Zealand) conducted a survey on the status of Australian beverages and benzene levels.

Focusing on beverages that were more likely to contain benzene, such as soft drinks and fruit juice, FSANZ sampled 68 beverages sold in retail outlets from March to April 2006. Independent analysis showed that 56 percent of beverages contained trace levels of benzene, ranging from 1 to 40 ppb. Over 90 percent of the 68 beverages screened were below the WHO guideline of 10 ppb.

Typically you would have to drink 10 bottles in a day to exceed the WHO drinking water upper limit.

Benzene is also present in petrol vapours, car exhaust fumes and cigarette smoke; the main way the general population is exposed to it is through environmental exposure. The UK Food Standards Agency has stated that people would need to drink more than 20 litres of a drink containing benzene as an impurity to get the same level of exposure as from the environment.

 

Sodium benzoate

In 2006 the Food Standards Agency (FSA) published the results of a survey measuring the levels of benzene in 150 soft drinks on sale in the UK. This was in response to allegedly dangerous levels of carcinogenic benzene in soft drinks as a result of sodium benzoate interacting with ascorbic acid (vitamin C). In more than two thirds of the samples tested the levels of benzene were undetectable, while 38 samples had levels between 1 and 10 ppb (parts per billion). The guideline level set by the World Health Organisation (WHO) for water is 10 parts per billion (ppb). 1 ppb is 1 part per billion, i.e. 1/1,000,000,000, which is equivalent to 1 microgram per kilogram (1ug/kg).

In May 2007 The Independent ran a story that sodium benzoate, a common preservative in soft drinks, damages the mitochondria in cells. Sodium benzoate (E211) is used in carbonated drinks to prevent mould growth. The article was headlined “Caution: Some soft drinks may seriously harm your health”. 


You can read The Independent article here



Here, Professor Sir Colin Berry, Emeritus Professor of Pathology responds:

Sodium benzoate is found naturally in cranberries, prunes, greengages, cinnamon, ripe cloves, and apples.  Its concentration when used as a preservative is limited by the FDA in the U.S. to 0.1% by weight in drinks but it is interesting to note that organically-grown cranberries and prunes can contain levels exceeding this limit. The International Programme on Chemical Safety found no adverse effects in humans at doses of 647-825 mg/kg of body weight per day so the safety margin is vast.

Benzene is ubiquitous in the environment and is found in “mid-Pacific-ocean air” at around 10ppt, in “background air” at around 2-10 ppb (USA data) and in the interior of a car will reach around 10-20ppb. When you fill the car with petrol the air will contain around 0.1-1ppm. Around 500ug of benzene is produced from an “average” cigarette and smokers have benzene in their breath.



Here, Professor Andrew Cockburn, Toxicologist, responds:

The approved food additives ascorbic acid (Vitamin C) and sodium benzoate can react to produce low levels of benzene when they are present in the same beverage. Exposure to low levels of benzene in industry over an extended period has been linked to the development of aplastic anaemia, which can lead to leukaemia.

The World Health Organisation (WHO) has set the acceptable level of benzene in drinking water at 10 parts per billion (ppb). In early 2006, tests performed on beverages in the USA found levels 2-5 times above this, sparking international concern. In response to this FSANZ (Food Standards Australia New Zealand) conducted a survey on the status of Australian beverages and benzene levels.

Focusing on beverages that were more likely to contain benzene, such as soft drinks and fruit juice, FSANZ sampled 68 beverages sold in retail outlets from March to April 2006. Independent analysis showed that 56 percent of beverages contained trace levels of benzene, ranging from 1 to 40 ppb. Over 90 percent of the 68 beverages screened were below the WHO guideline of 10 ppb.

Typically you would have to drink 10 bottles in a day to exceed the WHO drinking water upper limit.

Benzene is also present in petrol vapours, car exhaust fumes and cigarette smoke; the main way the general population is exposed to it is through environmental exposure. The UK Food Standards Agency has stated that people would need to drink more than 20 litres of a drink containing benzene as an impurity to get the same level of exposure as from the environment.

Author: Sense About Science

Document type: For The Record

Published: 3 July 2007


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