Benzene in soft drinks

Benzene has been detected sporadically at low levels in some soft drinks. It is thought that this occurs as a result of an interaction between the preservative sodium benzoate and ascorbic acid (vitamin C). Sodium benzoate is added as a preservative to prevent mould growing in the drinks and vitamin C may be used as an antioxidant or may be naturally present.

People who have inhaled very high levels of benzene in the workplace have been found to have an increased risk of cancer. Benzene is present in the atmosphere from exhaust emissions. On average, people breathe in 220 μg of benzene every day. For smokers cigarette smoking is the main source of exposure at 7900 μg per day.

There is no legal limit for benzene in soft drinks in the UK. The World Health Organisation (WHO) has set a guideline level for benzene in water of 10 μg/kg.

Following reports of benzene in some soft drinks in the US, the Food Standards Agency asked the UK soft drinks industry to provide information on levels in soft drinks sold in the UK. The Agency received aggregate summary data from tests carried out on 230 drinks on sale in the UK. The information provided contained limited details. The highest level of benzene found in the industry data was 8 μg per litre of soft drink. Most levels reported were much lower than this.

The survey reported here was conducted to provide the Agency with details on the possible presence of benzene in soft drinks in the UK.

Benzene has been detected sporadically at low levels in some soft drinks containing sodium benzoate and ascorbic acid (vitamin C). Sodium benzoate is added as a preservative to prevent mould growing in the drinks and vitamin C may be used as an antioxidant or be present naturally.

In this survey 150 drinks were collected from four regions in the UK from both supermarkets and independent shops. The samples consisted of concentrates (squashes), carbonated drinks and ready-to-drink still drinks.

The majority of the drinks contained benzoates and ascorbic acid, which are thought to react to form benzene. A limited number of mango juices and cranberry drinks were chosen as these fruits have been found to naturally contain benzene. In addition, a small number of drinks containing ascorbic acid and alternative preservatives such as sorbates or sulphur dioxide were chosen to help establish whether benzene was occurring from sources other than sodium benzoate.

Out of 150 soft drinks sampled, 107 (about 70%) did not contain detectable levels of benzene.

The levels of benzene reported in this survey will only make a negligible impact on people's overall exposure to benzene and so any additional risk to health is therefore likely to be negligible.

There are no statutory limits for benzene in soft drinks. The Food Standards Agency has drawn on the WHO guidelines for safe levels in drinking water as an appropriate comparator.

Four products contained average levels of benzene above 10 μg/kg: Co-op low calorie bitter lemon (2 products, 28 and 11 μg/kg), Popstar lemon and lime flavour still (17 μg/kg), Hyberry high juice blackcurrant squash (no added sugar) (12 μg/kg as purchased) and Morrison pineapple and grapefruit crush (no added sugar) (11 μg/kg). The Agency has asked the relevant companies to remove these products from sale.

The Food Standards Agency has asked the soft drinks industry to ensure that levels of benzene are kept as low as practicable.