Chemicals are added to food to preserve, flavor, thicken, or otherwise alter it in some desirable way. Used this way, the chemicals are called 'food additives'. In other contexts the same chemicals may be considered industrial chemicals or pesticides.
For example, sulfites were banned by FDA in 1986 for use on fruits and vegetables that are eaten raw, but are still allowed as a preservative in cooked and processed foods, and they occur naturally in wines and beers. They are also approved by EPA aspesticides, to prevent fungus and preserve grape crops. When eaten in foods, they induce allergy-like reactions in many people (FDA estimates that 1 in 100 people are sensitive to sulfites in food). When FDA approved their use as a food additive in the 1970s, sulfites were deemed to be Generally Recognized As Safe (GRAS) and exempted from FDA premarket approval requirements.
In 1974, the FDA allowed asbestos-contaminated salt produced by one company, United Salt in Houston, to be sold as table salt, as GRAS. FDA had even received comments from the trade group Salt Institute that it had looked at this type of salt – called diaphragm salt - and seen asbestos fibers by optical microscopy. Only in response to public outrage did FDA do a proper analysis of the salt at outside labs, using the more powerful electron microscopy, whereupon tens of millions of asbestos fibers per gram was found and FDA revoked its approval.
...Today, Pew released a report on Reproductive Toxicology reporting that "Less than 38% of [over 10,000] FDA-regulated additives have a published feeding study. For chemicals directly added to food, 21.6% [of about 3,000] have feeding studies necessary to estimate a safe level of exposure and 6.7% have reproductive or developmental toxicity data in FDA's database." It appears FDA and companies were often making safety decisions by comparing one chemical to another rather than doing an actual toxicology study. They were building a house of cards based on assumptions and unsupported extrapolations instead of direct scientific evidence.
How did our food regulations go so terribly wrong?
Please read on by Jennifer Sass at:http://switchboard.nrdc.org/blogs/jsass/usfda_allows_chemicals_in_food.html