This especially holds true for chemical preservatives; there are many for which you can say, “The U.S. Food and Drug Administration allows this substance in food and drink, but it is banned in the EU, and possibly elsewhere too.”
For example, the chemical azodicarbonamide is, according to FDA regulations, “Generally Recognized As Safe” in food — in densities no greater than 45 parts per million. But in most of the world, azodicarbonamide is used primarily in the manufacture of rubber and plastics. Various governments in Europe and Australia consider azodicarbonamide a “respiratory sensitizer” that can trigger asthmatic reactions, and in Singapore, using azodicarbonamide in food warrants high fines and lengthy prison sentences.
Azodicarbonamide made American headlines last February when the Subway sandwich chain, presumably responding to a petition started by a health-food blogger, announced that it would henceforth stop using the chemical in its bread.
And this week another company, presumably in response to a petition, announced plans to alter its recipes so that the products it sells in America are more in line with its offerings elsewhere in the world: the Coca-Cola company will stop adding bromiated vegetable oil to its American drink products. Bromiated vegetable oil contains bromide, which has proven useful as a flame retardant, though Japan and the European Union ban it for human consumption.
Too lax?
Why the wide discrepancy between the U.S. and worldwide views of such chemical additives? Is the United States too lax about food safety where chemicals are concerned — or is the European Union too strict?
In December 2011, Scientific American reprinted an Environmental Health News article discussing the pros and cons of using bromiated vegetable oil (BVO) as a food additive. On the pro side, there's no denying that the FDA has deemed BVO safe for people. But BVO critics countered that the FDA based this decision on scanty data from a study now several decades old, and the frontiers of scientific knowledge have advanced considerably since the 1970s.
Charles Vorhees is a Cincinnati toxicologist who studied the neurological effects of BVOs in the early 1980s. In 2011 Vorhees said, "Compounds like these that are in widespread use probably should be reexamined periodically with newer technologies to ensure that there aren't effects that would have been missed by prior methods … I think BVO is the kind of compound that probably warrants some reexamination."
There are definitely cases of people who developed massive health problems after excessive consumption of bromide. Consider this example from the 2011 SciAm article:
In 1997, emergency room doctors at University of California, Davis reported a patient with severe bromine intoxication from drinking two to four liters of orange soda every day. He developed headaches, fatigue, ataxia (loss of muscle coordination) and memory loss.
In a 2003 case reported in Ohio, a 63-year-old man developed ulcers on his swollen hands after drinking eight liters of Red Rudy Squirt every day for several months. The man was diagnosed with bromoderma, a rare skin hypersensitivity to bromine exposure. The patient quit drinking the brominated soft drink and months later recovered.
Those two people definitely suffered bad side effects from bromide ingestion — or was it from excessive bromide ingestion? After all, a common adage in medicine says that “the dose makes the poison.” In other words, anything is dangerous if consumed to excess — even pure, clean water will kill you if you drink too much too quickly.
And drinking two to eight liters of soda per day, every day, will wreck your health regardless of whether that soda contains BVO. Indeed, one of the authors of that 1997 study told SciAm as much:
"Any normal level of consumption of BVO would not cause any health problems — except the risk of diabetes and obesity from drinking that much sugar water," said Zane Horowitz, medical director of the Oregon Poison Center and author of the 1997 case study.
It's also worth remembering: the mere fact that a given chemical is used in the production of flame retardant and other non-edible or even toxic materials does not automatically make that chemical unsafe for human consumption.
There is a well-known joke/prank wherein people will discuss the dangers of the chemical “dihydrogen monoxide” (or even collect signatures on petitions urging that dihydrogen monoxide be banned).
Search online for information about dihydrogen monoxide, and you'll find a long list of scary and absolutely true warnings about it: used by the nuclear power industry, vital to the production of everything from pesticides to Styrofoam, present in tumors removed from cancer patients, and guaranteed fatal to humans in large quantities.
So is dihydrogen monoxide safe for human consumption? Of course. It's not just safe, it's mandatory: dihydrogen monoxide, the compound consisting of two atoms of hydrogen for every one of oxygen, is just another way of saying “water.”