EPA has removed 72 chemicals from the list of inert ingredients that can be added to pesticides. Such chemicals perform functions other than controlling pests. They include emulsifiers, solvents, aerosols, fragrances, dyes, and other substances that are not necessarily benign. The agency’s action comes in response to petitions dating back to 2006 from environmental groups that claim many inert ingredients in pesticides are hazardous. The groups urged EPA to require disclosure of 371 inert ingredients. But pesticide makers pushed back, claiming such information is proprietary. After floating the idea of requiring public disclosure of all pesticide ingredients, EPA reversed course and decided not to require disclosure of inert substances. Instead, the agency says that it will “evaluate potential risks of inert ingredients and reduce risks, as appropriate.” Some of the 72 chemicals subject to EPA’s rule are among the 371 substances mentioned in the petitions. None of them, however, are currently used in pesticides in the U.S. Environmental activists are urging EPA to quickly assess the other hundreds of inert ingredients that are added to pesticide formulations.