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 soft drinks from faulty equipment or other outside sources, they have been isolated and quickly remedied by recalls of the lots of potentially contaminated products.
Unfortunately, a far more problematic source of benzene contamination exists and it has nothing to do with a mechanical breakdown or human error. It has to do with a few simple chemical reactions between ingredients mixed together in the drinks themselves. This is on a global scale and there arenÃ¢â‚¬â„¢t going to be any recalls; at least not until after an FDA investigation.
It seems that over 15 years ago in an investigation that never became 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 (World Health Organization) of 10 ppb (parts per billion).
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 UK Food and Standards Agency has announced that it too has opened an inquiry into the problem and will launch its own full-scale investigation if excessive levels of benzene are discovered.