Pesticides
The Federal Insecticide, Fungicide, and Rodenticide Act divides the ingredients in pesticides into two groups: active and inert. An inert chemical, under this context, is one that does not have a toxic effect on the species the pesticide is meant to combat, but that does not rule out that it may still have a biological activity on other species, including being toxic to humans. Solvents, propellents, preservatives, among others, are thus considered inert ingredients in pesticides.
Since 1997, the United States Environmental Protection Agency has recommended that pesticide manufacturers label the non-active ingredients as "other ingredients" rather than "inert" to prevent misinformation to the public.
Read more about this topic: Inert