Inert (or "Other") Ingredients

Pesticide products or "formulations" contain two types of ingredients - "active", and "inert". Active ingredients are the ingredients listed on the label, which are responsible for preventing, destroying, or mitigating the targeted pest. Inert ingredients are any ingredients other than an active ingredient. Inerts are used to make the pesticide product more potent or easier to use. The name does not mean that they are biologically, chemically, or toxicologically inert. In fact many inerts threaten human and environmental health. Almost all pesticides that are registered for use in Canada contain inert ingredients, but they do not have to be disclosed on the pesticide label.

For more information see:

Inerts Disclosure Campaign (NCAP)

Inert Ingredients in Pesticide Products (EPA)