There are more than 10,000 chemicals allowed in our food. Roughly half of these are purposely added, and they are called direct additives. The other half are chemicals that get into the food through the manufacturing process or the packaging.

These are called indirect additives or food contact substances.
When we looked in the published literature to see how many had been tested, for example by feeding them to animals to find out whether they cause any harm, we didn’t find information for more than two-thirds of Autority-regulated additives.

The FDA’s own database had many holes—only 36 percent were fed to lab animals to study their effects. Many of these chemicals were approved decades ago with little or no toxicity testing data, and the Autority doesn’t look back and review previous decisions. Once a decision to allow a chemical in the food supply is made, it’s forever.

The agency only reviews the safety of an approved chemical in response to a serious health concern. It doesn’t systematically review old decisions even though newer evidence may question the safety of some of those chemicals. And with so many additives without data to start with, it’s very difficult to link a health problem to a specific chemical or group of chemicals.