This piece comes from the Center for Public Integrity, a nonpartisan, nonprofit investigative news organization.

Companies have added thousands of ingredients to foods with little to no government oversight. That's thanks to a loophole in a decades-old law that allows them to deem an additive to be "generally recognized as safe" — or GRAS — without the U.S. Food and Drug Administration's blessing, or even its knowledge.

The loophole was originally intended to allow manufacturers of common ingredients like vinegar and table salt — when added to processed foods — to bypass the FDA's lengthy safety-review process. But over time, companies have found that it's far more efficient to take advantage of the exemption to get their products on shelves quickly. Some of these products contain additives that the FDA has found to pose dangers. And even ingredients the agency has agreed are GRAS are now drawing scrutiny from scientists and consumer groups that dispute their safety.

Critics of the system say the biggest concern, however, is that companies regularly introduce new additives without ever informing the FDA. That means people are consuming foods with added flavors, preservatives and other ingredients that are not reviewed at all by regulators for immediate dangers or long-term health effects.

The vast majority of food additives are safe. Some, however, have proved to cause severe allergic reactions or other long-term health effects. Scientists and advocates worry about the growing number of ingredients that the FDA doesn't know about and is not tracking.

Rather than going through the painstaking FDA-led review process to ensure that their new ingredients are safe, food companies can determine on their own that substances are "generally recognized as safe." They can then ask the FDA to review their evaluation — if they wish. Or they can take their ingredients straight to market, without ever informing the agency.

"FDA doesn't know what it doesn't know," said Steve Morris of the Government Accountability Office, which published a report in 2010 that found that "FDA's oversight process does not help ensure the safety of all new GRAS determinations."

And even when a company does go through the FDA review process, safety decisions have been criticized. For example, advocacy groups and lawsuits allege that mycoprotein, a type of fungus used in vegetarian products, has caused consumers to suffer a range of reactions, including nausea and anaphylactic shock. The complaints prompted the Center for Science in the Public Interest to urge the FDA in 2011 to revoke the ingredient's GRAS status.

For a company to determine that an ingredient is "generally recognized as safe," it must establish that the additive's safety is commonly understood by qualified scientific experts.

But some ingredients defy consensus, as consumers, scientific groups and sometimes even the FDA have pointed out. Even GRAS additives that have been used in food for decades are now coming under fire as their uses expand and scientific research emerges that casts doubt on their safety.

This is true of one of the most known — and vilified — GRAS additives: partially hydrogenated oil, a form of trans fat. Widely used in food products including fried foods and cake mixes, trans fats have been named by public health experts as a contributor to heart disease, stroke and Type 2 diabetes. Despite strong pushback from industry, the FDA in November 2013 made a tentative determination that artificial trans fats should not have GRAS status, and the agency is likely to make that determination final this summer.

But it's the ingredients the public doesn't know about that have critics of the GRAS system most worried.

Researchers for the Pew Charitable Trusts and the Natural Resources Defense Council say that allowing companies to make safety determinations without telling the FDA makes it nearly impossible to identify whether there are health effects caused by long-term exposure to certain ingredients.

Their concerns are heightened because safety decisions often rest in the hands of a small group of scientific experts selected by companies or consulting firms with a financial incentive to get new ingredients on the market. Several of these scientists, a Center for Public Integrity investigation found, previously served as scientific consultants for tobacco companies during the 1980s and 1990s, when the tobacco industry fought vigorously to defend its products.

The GRAS loophole was born in 1958. Americans were growing concerned about the increased use of preservatives and other additives in food, so Congress passed — and President Dwight Eisenhower signed — the first law regulating ingredients added to food.

To restore confidence, the law set up a system requiring companies to submit new ingredients to an extensive FDA safety review before going to market.

"Congress had a clear understanding of what 'generally recognized as safe' means, but that's not the understanding that basically prevailed," said Scott Faber, vice president of government affairs for the Environmental Working Group, a nonprofit advocacy group seeking reforms to the GRAS system. "There are plenty of ingredients that are receiving GRAS status the safety of which are in dispute."

In the past five decades, the number of food additives has skyrocketed — from about 800 to more than 10,000. They are added to everything from baked goods and breakfast cereals to energy bars and carbonated drinks.

Meanwhile, the FDA's food additive approval system has slowed to a crawl — the average review takes two years, but some drag on for decades.

"The food additive review process is a highway that is constantly gridlocked. If the food additive road doesn't go anywhere, what do I do?" asked Stuart Pape, a Washington, D.C., attorney who consults for companies that manufacture food additives. "GRAS is the other pathway."

The FDA has publicly acknowledged the GRAS system's shortcomings.

"We simply do not have the information to vouch for the safety of many of these chemicals," Michael Taylor, the FDA's deputy commissioner for foods, told The Washington Post last year.

Meanwhile, industry scientists and lawyers contend that safety concerns are overblown, and that major reforms designed to increase government oversight would cripple the resource-depleted FDA and stifle food innovation.

"It isn't the Wild West out there," said Stanley Tarka, a toxicologist and industry consultant. "We have the safest food supply in the world."

For the full investigation, head to the Center for Public Integrity's site. Follow the center on Twitter @Publici, or sign up for its newsletter.

