By Steven DiJoseph
Acting on test results in the U.S. that found unacceptably high levels of benzene (a known carcinogen) in samples of popular soft drinks, BritainÃ¢â‚¬â„¢s Food Standards Agency (FSA) ordered similar tests that yielded the same outcome.
The FSA, the British equivalent of the FDA in the U.S., tested 230 different drinks and found some contained benzene in concentrations of up to eight parts per billion (ppb).
Although the UK has no formal restriction on the amount of benzene in soft drinks, the legal limit permitted in drinking water is only 1 ppg.
Benzene is a dangerous toxin that has been linked to leukemia and other cancers of the blood. It is a component of other carcinogens such as fossil-fuel exhaust fumes.
One of the problems with benzene is that its carcinogenic effects are currently quantified in terms of life-time exposure. The exact amount of benzene and the duration of exposure needed to produce a serious health risk are far from certain. In minute amounts, the potential for harm is even less definite.
People living or working near high concentrations of exhaust fumes are exposed to far greater daily doses of benzene than have been found in soft drinks and drinking water, yet most governments and the World Health Organization (WHO) have set extremely low guidelines for the chemical when it is likely to be consumed by humans in a commercial product or public water supply.
Thus, while many experts and health officials are not alarmed by the presence of small amounts of the toxic chemical, others are not as willing to assume that low levels of benzene contamination are harmless or without potentially dangerous long-term effects on humans.
As we reported last week, if you asked most people how a poisonous chemical like benzene could wind up in a commercially produced soft drink, they would answer that it would probably be the result of a breakdown in the packaging process. They would be right, and wrong, however.
While there have been some episodes of benzene leaking into commercial products, such as soft drinks and bottled water, from faulty equipment or other outside sources, they have been isolated and quickly remedied by recalls of the lots of potentially contaminated products.
The far more problematic source of benzene contamination in commercially produced drinks has nothing to do with mechanical breakdowns or human error. Instead, it is the by-product of a few simple chemical reactions between ingredients mixed together in the drinks themselves. This problem is on a global scale and has yet to prompt serious concern on the part of health officials. That may all change as a result of the present findings, however.
Over 15 years ago, in an investigation that was never made public, and after which the beverage industry promised to Ã¢â‚¬Å“reformulateÃ¢â‚¬Â its ingredients and otherwise Ã¢â‚¬Å“get the word outÃ¢â‚¬Â about the problem, the FDA found unacceptable amounts of benzene in a number of soft drinks.
The culprit was a chemical reaction any child could perform with a store-bought chemistry set. Sodium benzoate (a preservative added to extend shelf-life by killing bacteria under acidic conditions) and ascorbic acid (vitamin C Ã¢â‚¬â€œ artificially added to prevent spoilage and extend shelf-life or naturally occurring in fruits and vegetables) can react to produce benzene at levels above permissible limits.
Ascorbic acid will react with metals (like iron and copper found in water) to create hydroxyl radicals. Meanwhile, when exposed to an acidic environment (as found in many soft drinks), sodium benzoate breaks down into benzoic acid. When the Ã¢â‚¬Å“free radicalÃ¢â‚¬Â hydroxyl reacts with the benzoic acid, the carbon dioxide is removed and what is left is benzene.
Since the matter was handled informally in 1990-1991 and all parties concerned seemed to have come to a reasonable agreement that the problem needed to be addressed and resolved, no action was taken by the FDA to impose penalties or regulations on the soft drink industry. Reformulation and dissemination of the information by the industry was to be the solution.
One reason for the rather lax way in which the problem was handled was the fact that the risks posed by benzene were (and still are for that matter) looked at as a consequence of life-time exposure to the chemical. The problem was regarded as a short-term one that would be resolved long before any harm to humans might occur.
Follow-up tests in 1993 found no contamination and an article in the Journal of Agriculture and Food Chemistry discussed the problem, although not in a forum that the public was likely to read.
The problem now seems to be that 15 years of informality has caused the message to have been lost. This can be attributed to new soft drink companies (since 1993), foreign companies that may not have gotten the message at all or only to a limited extent, small companies that do not have sophisticated quality control systems, and literally thousands of new soft drink products containing both sodium benzoate and ascorbic acid (launched worldwide in past five years).
Thus, testing by independent labs prompted by consumer advocates or as a result of disclosures by whistleblowers (or internal documents) from within the industry have identified levels of benzene in some soft drink samples as being up to 5 times the limit for drinking water set by WHO of 10 ppb.
While the ingredients that produce the benzene are common in a wide range of soft drinks, their presence is hardly necessary. Vitamin C is an ingredient that adds nothing to the product itself. In fact, it is now used as an advertising gimmick to boost sales or to allow the marketing of soft drinks to children as health drinks.
Experts see the problem as one that is easily remedied since ascorbic acid is not critical a critical additive and can safely be left out of soft drinks. Moreover, in fruit and vegetable drinks where ascorbic acid occurs naturally, sodium benzoate can be eliminated as an additive to avoid the chemical reaction problem.
The FDA now acknowledges it is nearing the end of its testing and will soon reach a decision as to what further action should be taken. The FSA, however, seems to be just beginning it s probe.
Two important issues that have fueled the current debate and which consumer advocates believe must be resolved are: (1) the publicÃ¢â‚¬â„¢s right to know what is contained in commercial products that are marketed for human consumption; and (2) the need for regulations that place the same restrictions on benzene in soft drinks as those already in place with respect to drinking water.