The NPA is the group behind the certification of natural personal care products, like Burt's Bees and Nature's Way (see here for a list of certified "natural" personal care products). They've been around since 1936, has a strong presence in Washington, and "represents more than 10,000 retailers, manufacturers, wholesalers and
distributors of natural products, including foods, dietary supplements, and health/beauty aids."
They have more than just environmental reasons and warm&fuzzy feelings to certify products - this is a big business. In the U.S. in 2008, according to the Nutrition Business Journal, people spent $10.1 billion on natural/organic personal care and household items. The problem is that the industry isn't quite as regulated as one might hope, so snakeoil salesmen are getting through with claims of "natural" on their products that are mostly comprised of synthetic materials.
"Natural generally means that the product's ingredients are derived from renewable resources like plants and minerals," the WSJ reports. "It is not to be confused with organic, which refers to a method of agriculture that avoids the use of pesticides and antibiotics. But there is currently no uniform standard among manufacturers for use of the word in home-care products."
The NPA requires that all products that are labeled or branded "Natural" must be made according to specific processes with at least 95% all natural ingredients (not counting water) with the remainder of ingredients limited to "allowed synthetics," which are only allowed when there is not a readily available, commercially viable, natural alternative ingredient equivalent; when there are no suspected human health hazards as identified by appearing in the authoritative lists of prohibited ingredients; when required for trade‐acceptable product; when made using allowed processes (specified by the NPA); when synthetic does not appear on the Prohibited Processes nor Prohibited Ingredients list; and at no more than a 5% cumulative level in the final formulation (calculations do not include water).
Products like parabens are phthalates not allowed. You also can't test on animals, at least 60% of your product line has to meet the NPA standards, and the packaging - not just the product - has to be environmentally friendly.
The seal should start appearing on home care products in the next few months.