Organic production has been practiced in the United States since the late 1940s. From that time, the industry has grown from experimental garden plots to large farms with surplus products sold under a special organic label. Food manufacturers have developed organic processed products and many retail marketing chains specialize in the sale of "organic" products. This growth stimulated a need for verification that products are indeed produced according to certain standards. Thus, the organic certification industry also evolved.
More than 40 private organizations and state agencies (certifiers) currently certify organic food, but their standards for growing and labeling organic food may differ. For example, some agencies may permit or prohibit different pesticides or fertilizers in growing organic food. In addition, the language contained in seals, labels, and logos approved by organic certifiers may differ. By the late 1980s, after an attempt to develop a consensus of production and certification standards, the organic industry petitioned Congress to draft the Organic Foods Production Act (OFPA) defining "organic".
The National Standards on Organic Agricultural Production and Handling (NOP rule) was issued on December 21, 2000, by USDA’s Agricultural Marketing Service. The standards in the NOP rule are similar to most of the standards organic producers and handlers currently use, and are intended to be flexible enough to accommodate the wide range of operations and products grown and raised in every region of the United States. The Organic Foods Production Act and the NOP rule require that agricultural products labeled as organic originate from farms or handling operations certified by a state or private agency that has been accredited by USDA. Neither the Organic Foods Production Act nor the NOP rule address food safety or nutrition. - EPA