In several posts (here, here, and here) on The Style Page blog, I've highlighted various activities to set standards and certification rules for what constitutes "natural" or "organic" personal care products (note that "natural" and "organic" are not necessarily synonyms). Vendor participation in these programs is voluntary.
Mischo Beauty posted an article about the U.S. Department of Agriculture's National Organic Program, or NOP. According to the USDA,
The National Organic Program (NOP) develops, implements, and administers national production, handling, and labeling standards for organic agricultural products. The NOP also accredits the certifying agents (foreign and domestic) who inspect organic production and handling operations to certify that they meet USDA standards.
In another article, Mischo Beauty highlights another voluntary program to certify products as "biodynamic."
Bottom line: Given the plethora of standards-setting and certification activities, an international voluntary standard that specifies what constitutes organic personal care products should be established through ISO.