The Environmental Working Group (EWG) is hard at work again, this time taking a look at the chemicals used in both conventional and organic processed foods. EWG is best known for creating the dirty dozen list of fruits and vegetables to avoid and the best sunscreens to use. This new report follows the groups ongoing theme of helping consumers understand whats in the products they buy.

The term processed may have negative connotations, but processed doesnt necessarily mean a microwavable dinner or a bag of chemical-laden chips. Processed simply means something was done to the food after it was harvested or killed. A canister of organic, plain steel-cut oats is considered processed but so is a packet of instant oatmeal with added sugars, flavors and preservatives. The difference lies in how they were processed.

EWGs new report, Organic: The Original Clean Food, reminds consumers that when a processed food is certified organic, it contains no artificial preservatives, colors or flavors. There are also fewer than 40 synthetic substances that organic packaged foods can contain, and those substances must be reviewed by independent and government experts.

However, conventional processed foods can contain artificial preservatives, colors and flavors. They can also contain thousands of chemicals. Most of those chemicals never need to go through a government approval process. The Food and Drug Administration (FDA) relies on the chemical manufacturing companies to declare the chemicals safe.