USDA's National Organic Standards

As of October 21, 2002, the U.S. Department of Agriculture (USDA) has put in place a set of national organic standards that food labeled organic must meet, whether it is grown domestically or imported from other countries. To determine whether a food meets the USDA's standards, a U.S. Government-approved certifier inspects the farm where the food is grown to make sure the farmer is following all the necessary rules. Companies that handle or process organic food before it gets distributed to stores or restaurants must be certified as well.

 Along with the national organic standards, the USDA has developed strict new labeling rules to help consumers know the exact organic content of the food they buy. The USDA organic seal, increasingly common after October 2002, indicates a product is at least 95% organic.
 

Single-ingredient foods:

The USDA label may appear on stickers on the packaging, outer skin, or display signs for single-ingredient foods such as produce, milk, meat, eggs, or cheese.

Foods with more than one ingredient:

There are four categories for organic foods with more than one ingredient. The first three categories prohibit the inclusion of any ingredients produced using genetic engineering, irradiation, or sewage sludge. 

100% Organic:

Only products that have been exclusively produced using organic methods carry this label.

Organic:

At least 95% of the ingredients (by weight, excluding water and salt) in products carrying this label must be organically produced.

Made with organic:  
Products with 70 to 95% organic ingredients may display “Made with organic [with specific ingredient or ingredients listed]” on the front panel.

Less than 70% organic:

Products with less than 70% organic ingredients may list these specific items in the ingredient panel.

The actual percent of organic content may be displayed on all products, regardless of label category. However, the rule specifies the actual dimensions that are allowed in displaying the content, and, as noted earlier, the percentage for products with less than 70% organic ingredients can only be displayed in the information panel. In all four labeling categories, the product cannot use both organic and non-organic versions of the same ingredient.

Note that labels may also make other truthful claims about their food content, such as “natural,” “free-range,” and “hormone-free,” but these claims are not interchangeable with “organic.”

This is a great non-profit website: The Center for Science in the Public Interest (CSPI)

The Center for Science in the Public Interest (CSPI) is a nonprofit education and advocacy organization that focuses on improving the safety and nutritional quality of the food supply. CSPI makes sure that the farmers and corporations lves up the organic standards. CSPI seeks to promote health through educating the public; influencing laws, and encouraging more responsible corporate practices.

More on Organic Standards, See CSPI