The Green Products Alliance

 The USDA has a legal definition for "natural", but it applies only to meat and poultry; "those products carrying the “natural” claim must not contain any artificial flavoring, color ingredients, chemical preservatives, or artificial or synthetic ingredients, and are only “minimally processed” defined by USDA as a process that does not fundamentally alter the raw product."

The USDA National Organic Program defines non-synthetic as "a substance that is derived from mineral, plant, or animal matter and does not undergo a synthetic process".  They define a synthetic as "a substance that is formulated or manufactured by a chemical process or by a process that chemically changes a substance extracted from naturally occurring plant, animal, or mineral sources, except that such term shall not apply to substances created by naturally occurring biological processes."

Consumers Union, publisher of Consumer Reports, which is an independent, nonprofit testing and information organization serving only consumers, states; "Natural is a general claim that implies that the product or packaging is made from or innate to the environment and that nothing artificial or synthetic has been added. There is currently no standard definition for the term except for meat and poultry products. Unless otherwise specified, there is no organization independently certifying this claim. The producer or manufacturer decides whether to use the claim and is not free from its own self-interest."