Benzene: A Hazardous Chemical Linked to Increased Cancer Risk
 |
| Benzene, a result of the reaction between the preservative sodium benzoate and ascorbic acid (vitamin C) found in soft drinks, poses a cancer risk. In the image: Molecular structure model of benzene – C6H6 |
Since 1990, the U.S. Food and Drug Administration (FDA) has warned the American soft drink industry about benzene levels in soft drinks that are 2.5 to 5 times higher than the World Health Organization’s (WHO) permissible limit for drinking water, which is set at 10 ppb (parts per billion).
However, this issue was not publicly addressed as the soft drink industry promised to reformulate their products to reduce this harmful substance.
Concealing Information Is Not a Good Solution
According to an internal memo from the FDA, as of December 1990, the agency was informed by soft drink companies Cadbury Schweppes and Koala Springs, Australia, about the risk of benzene in soft drinks.
This information was discussed at a conference involving the FDA and the American Soft Drink Association (ASDA), representing soft drink manufacturers such as Coca-Cola, PepsiCo, and Cadbury Schweppes.
The manufacturers promised to change their formulas to eliminate the risk, and thus the issue was kept quiet.
In 1993, the FDA conducted an inspection but found no issues. However, since then, many new manufacturers have emerged who may not have been aware of this information.
 |
| Glen Lawrence, one of the chemists who tested benzene for the FDA in the early 1990s (Image: VNN) |
Moreover, this information was not widely published enough to attract attention from other countries to take timely action. From January 2002 to now, over 1,500 soft drink products containing sodium benzoate and vitamin C or citric acid have been circulating in Europe, Latin America, and North America.
Is There a Carcinogenic Toxin in Soft Drinks?
The issue arises from two commonly found components in soft drinks: the preservative sodium benzoate and ascorbic acid (vitamin C), which can react together to form benzene.
Sodium benzoate, designated as E211, is commonly used as a preservative in the food industry. Ascorbic acid, or vitamin C, found in fruits and fruit juices, is often added to food and beverages as an antioxidant to extend product shelf life.
The reaction mechanism was explained by Glen Lawrence, one of the chemists who tested benzene for the FDA in the early 1990s:
 |
Soft drinks (Image: VNN) |
1. Initially, ascorbic acid reacts with iron and copper metals found in water to form hydroxyl free radicals.
2. Simultaneously, sodium benzoate in the acidic environment of soft drinks produces benzoic acid.
3. Hydroxyl radicals will further react with benzoic acid, releasing CO2 and forming benzene.
According to Lawrence, this reaction can occur in beverages and foods containing sodium benzoate and vitamin C, including naturally occurring vitamin C in fruit juices. Therefore, fruit juices and soft drinks containing vitamin C should not use sodium benzoate as a preservative.
Currently, this issue is becoming a hot topic in the U.S. and European countries. The UK Food Standards Agency (FSA) is conducting an investigation following test results from 230 soft drink samples showing that average benzene levels exceed permissible limits for drinking water. France and Germany are also beginning to take action…
Meanwhile, according to the list of food additives permitted for use in food issued by the Ministry of Health of Vietnam, sodium benzoate and benzoic acid are still allowed in soft drink products such as pickled fruits, canned fruit nectars, sports drinks, and herbal beverages…
