Capping seven years of negotiations among farmers food processors and environmentalists the federal standard would replace the existing patchwork of state organic labeling regulations. Products meeting the definition of organic could bear a USDA seal of certification issued by state or private agencies accredited by USDA. To qualify for the organic seal raw products must be 100% organic (produced using environmentally sound procedures and naturally occurring substances or any of the very few approved synthetic substances) while processed foods must contain at least 95% organic ingredients (not counting water and salt). Those containing 50% to 94% organic ingredients can be labeled "made with certain organic ingredients." The proposed rule did not address the controversial question of whether or not irradiated foods or bioengineered products could be labeled organic. It gave the Secretary of Agriculture authority to add synthetic or genetically engineered chemicals to the list of products approved for use on organic foods. The comment period for the proposed rule ends March 18 and a final rule is expected by the end of 1998. Sen. Patrick Leahy (D-VT) author of the Organic Foods Production Act of 1990 predicted the final rule would become "the world standard" facilitating the marketing of U.S. organic foods abroad. Some food industry analysts believe the new rule will cause processors to reformulate some product lines and revise labeling and marketing claims.