Reversing a decade-old decision, the U.S. Environmental Protection Agency announced Tuesday that it plans to require pesticide manufacturers to disclose to the public the inert ingredients in their products.

An inert ingredient is anything added to a pesticide that does not kill or control a pest.

In some cases, those ingredients are toxic compounds, but companies do not identify them on pesticide labels.

Nearly 4,000 inerts – including several hundred that are considered hazardous under other federal rules – are used in agricultural and residential pesticides.

The EPA’s announcement that it will initiate the rulemaking comes 11 years after it had first been petitioned by environmental groups and state officials seeking public disclosure of the ingredients. In 2001, the agency denied those petitions filed by ten state attorney generals and an environmental coalition, and its decision was upheld by a federal judge in 2004.

Now, under a new administration, the EPA decided that drafting a new regulation will “increase transparency” and help protect public health.

“EPA believes disclosure of inert ingredients on product labels is important to consumers who want to be aware of all potentially toxic chemicals, both active and inert ingredients, in pesticide products,” according to the agency’s website.

Formaldehyde, bisphenol A, sulfuric acid, toluene, benzene and styrene are among the ingredients that are allowed in pesticides but are not identified on labels. Some are carcinogens, while some may cause reproductive or respiratory problems if people are exposed. Other inerts seem benign, such as coffee grounds, sunflower oil and licorice extract.

One goal of the planned rule is that pesticide companies would be more likely to replace toxic chemicals if they must identify all ingredients on their labels.