By Steven DiJoseph
As the issue of benzene in soft drinks heats up, several developments have occurred on both sides of the Atlantic. While the revelations have seemed to prompt remedial action in the UK, the same cannot be said of the steps taken by the Food and Drug Administration (FDA) in the U.S.
Acting on test results in the U.S. that found unacceptably high levels of benzene (a known carcinogen) in samples of popular soft drinks, Britain’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 ppb. Thus, the FSA ordered retailers to halt all sales of four soft drinks found to contain benzene in excess of that level.
In the U.S., however, the FDA is being criticized by a number of consumer advocates and public watchdog organizations, such as the Environmental Working Group (EWG), for a less than stellar performance in the matter.
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 previously reported, 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.
Over 15 years ago, in an investigation that was never made public, and after which the beverage industry promised to “reformulate†its ingredients and otherwise “get the word out†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 – 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 “free radical†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.
Although 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, the EWG sees voluntary agreements as unworkable.
In fruit and vegetable drinks where ascorbic acid occurs naturally, sodium benzoate can actually be eliminated as an additive to avoid the chemical reaction problem altogether.
Two important issues that have fueled the current debate and which consumer advocates believe must be resolved are: (1) the public’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.
While the FSA seems to be serious about its probe and the actions it is prepared to take to protect the public from even an uncertain degree of harm, the FDA has found itself caught up in a series of missteps.
Only a week ago, the FDA denied any evidence of a benzene problem. Then, a few days later, the agency backtracked and admitted its scientists had found benzene in soft drinks at levels greater than the “safe†standard set for drinking water.
Although the FDA attempted to excuse the about-face by claiming that the levels detected (above 5 ppb) still do not pose a health hazard, the position is in clear conflict with the FSA actions and the WHO view that since “benzene is carcinogenic to humans…no safe level of exposure can be recommended.”
Adding even more controversy to the FDA’s actions of the past week is the revelation that research by the EWG discovered an FDA report that showed some soft drinks contained unsafe levels of benzene.
The 2003 report known as the Total Diet Study incorporated data from research done between 1995 and 2001 that showed 19 of 24 (79%) diet soda samples tested contained benzene levels above 5 ppb.
According to the EWG, benzene levels as high as 55 ppb were found and the average level detected was 19 ppb. Both figures far exceeded the 5 ppb tap water standard.
In a separate study, the FDA found one cola containing a benzene level of 138 ppb. That study was looking for volatile organic compounds in foods and appeared in a 2003 issue of the Journal of Agricultural and Food Chemistry.
Thus, the EWG and consumer advocates are concerned over the FDA’s apparent lack of candor vis-à-vis the public. The assumption had been that between 1991 and now the original problem with benzene had been corrected under the voluntary agreement and was only now resurfacing.
Now, it appears the problem may never have been completely addressed by the soft drink industry between 1991 and 2005 and that the FDA was aware of the non-compliance since at least 1995.
This brings into question the FDA’s commitment to keeping benzene at safe levels in the food supply and it may also demonstrate the influence of the American Beverage Association has on the agency’s determinations. In any event, it certainly shows that the so-called voluntary agreement by the soft drink industry to reformulate its products and monitor benzene levels may have been nothing more than an empty promise.
