Benzene in soft drinks

Benzene in soft drinks has received some scrutiny because benzene is a carcinogen, or cancer-causing agent. Its levels are regulated in drinking water nationally and internationally, and in bottled water in the United States, but only informally in soft drinks. Within recent years, some soft drinks have been found to contain high levels of benzene. Benzene contamination of soft drinks is a public health concern and has caused significant outcry among environmental and health advocates.

Limit standards in drinking water
Various authorities have set limits on benzene content in drinking water. The following limits are given in parts per billion (ppb).
 * World Health Organization (WHO): 10 ppb (or 10 μg/kg) (WHO notes that benzene should be avoided whenever technically feasible.)
 * Republic of Korea (South Korea): 10 ppb
 * Canada: 5 ppb
 * United States: 5 ppb
 * European Union: 1 ppb
 * State limits within the United States: California, New Jersey, and Florida: 1 ppb

The EPA and California have set public health goals for benzene of 0 ppb and 0.15 ppb respectively.

Environmental exposure to benzene
Benzene in soft drinks should be seen in the context of wider environmental exposure. Taking the worst example found to date, of a soft drink containing 87.9ppb benzene, someone drinking a 500ml can would ingest 44μg (micrograms) of benzene. Whilst there is no justification for a soft drink to contain high levels of benzene ("There is a difference here between a small and unavoidable risk, and a small but avoidable risk.” ), the casual consumption of such a drink is unlikely to pose a significant health hazard to a particular individual (see, for example, the EPA IRIS document on benzene ). However, spread out over billions of people consuming soft drinks each day, there would be a small number of cancers caused by this exposure.

The UK Food Standards Agency has stated that people would need to drink at least 20 litres per day of a drink containing benzene at 10 μg to equal the amount of benzene you would breathe from city air every day. Daily personal exposure to benzene is determined by adding exposure from all sources.
 * Air: A European study found that people breathe in 220μg of benzene every day due to general atmospheric pollution. A motorist refilling a fuel tank for three minutes would inhale a further 32μg. . The estimated daily exposure from "automobile-related activities" is 49 μg and for driving for one hour is 40 μg.
 * Smoking: For smokers, cigarette smoking is the main source of exposure: estimates are 7900μg per day (20-cigarette-per-day smoker), 1820 μg/day, and 1800 µg/day.
 * Passive smoking: Benzene intake from passive smoking is estimated at 63 μg/day (Canada) and 50 µg/day.
 * Diet and drinking water: 0.2 – 3.1 μg/day

Formation in soft drinks
The key ingredients leading to the formation of benzene are ascorbic acid (vitamin C, E300) and benzoic acid, added in form of its salts sodium benzoate (E211), potassium benzoate (E 212), or calcium benzoate (E 213). Benzene can also form by reaction of erythorbic acid and benzoic acid. Citric acid is not thought to induce significant benzene production in combination with benzoic acid, but some evidence suggests that in the presence of the reaction of ascorbic or erythorbic acid and benzoic acid, citric acid may accelerate the production of benzene.

Other factors that affect the formation of benzene are heat and light. Storing soft drinks in warm conditions speeds up the formation of benzene.

Calcium disodium EDTA and sugars have been shown to inhibit benzene production in soft drinks.

The International Council of Beverages Associations has produced advice to prevent or minimize benzene formation.

1990s
In 1990 a North Carolina study reported having found unsafe levels of benzene in bottles of Perrier for sale in the United States. The parent company of Perrier shifted from explanation to explanation on the issue, finally stating that it was an isolated incident of a worker having made a mistake in the filtering procedure.

In the early 1990s, the soft drink industry initially approached FDA with concerns about benzene formation in soft drinks. Following testing, FDA asked manufacturers to voluntarily reformulate. By 1993, FDA determined that most drinks had little benzene contamination.

In 1993, Professor Glenn Lawrence of Long Island University published research showing how benzene could be formed when benzoic acid and vitamin C react.

In the summer of 1998 a number of well known soft drinks manufacturers had to withdraw large quantities of their products from sale after benzene contamination in some production plants was discovered.

2005
In November, 2005, the FDA received test results conducted by private citizens that benzene was forming at low levels in several types of beverages.

In December 2005, Germany's Federal Institute for Risk Assessment (Bundesinstitut für Risikobewertung) published a review of benzene's possible formation in foods and drinks.

2006
In February, 2006, an unnamed former chemist at the FDA publicly revealed that benzene may be created as part of a chemical reaction during production of soft drinks, particularly those having an orange flavor. Full scale investigations immediately started at the Food Standards Agency (UK) and in Germany to reveal exactly which amounts of benzene, if any, were present, with several other organizations awaiting their findings.

Of equal concern, the chemist told the media that the soft drink industry and the FDA have known of this problem for 15 years, and supports himself with document copies explaining how benzene is a possible byproduct of these ingredients that exist in over a thousand soft drinks. More than extremely small trace amounts found after investigation would be of major concern, as benzene is a very aggressive carcinogen even in small amounts, and may among other things lead to leukemia.

The United Kingdom's Food Standards Agency released results on March 31 2006 for 150 beverages. Its results showed 43 beverages contained benzene, four of which contained levels above the World Health Organization drinking water standards (10 ppb). These four were withdrawn from sale.

In April 2006, the Korea Food and Drug Administration (KFDA) announced that it had detected benzene in 27 out of 30 vitamin-enriched drinks on sale in South Korea. It said the detected amount of benzene – ranging from 5.7 to 87.8 ppb – was not harmful to humans but advised manufacturers of beverages containing more than 10 ppb of benzene to voluntarily recall their products.

The FDA released preliminary results in May 2006 for 100 beverages showing that many soft drinks contained low levels of benzene (less than 5 ppb, the federal drinking water limit) while four drinks contained amounts above the standard. Two of these drinks contained amounts 15-18 times above the drinking water standard. Many of the products showed large variations in the amount benzene they contained. The FDA stated that it is working with manufacturers to reformulate products that contain benzene above the federal drinking water standard.

These test results are both lower and more accurate than a previous long-term study by the FDA. In the Total Diet Study that FDA conducted from 1996-2001 to determine the amounts of volatile organic compounds in various foods, FDA used an analytical procedure that caused more benzene to form in the drinks during the test.

The FDA emphasized that most beverages contain levels below 5 ppb and pose no risk to consumers. Furthermore, there are no standards for beverages beyond drinking and bottled water. A watchdog organization, the Environmental Working Group, had previously called on the FDA to release its results. The EWG also criticized the FDA for not acting on the Total Diet Study results showing the nearly 80% of the diet soft drinks exceeded the federal drinking water standards.

On 9 June 2006, Health Canada released its study results of benzene levels in beverages. Four products had levels above the Canadian guideline of five micrograms per litre for benzene in drinking water.

On August 24, 2006, two soft drink manufacturers agreed to settle a class-action lawsuit that had been filed by a group of parents in the District of Columbia Superior Court. The two companies, Zone Brands Inc., maker of "BellyWashers" products, and TalkingRain Beverage Co., denied that their products were harmful, but agreed to change the ingredients in their drinks.