A: I am answering this question by using information from the EPA government website. The EPA issued Pesticide Regulation Notice 97-6 after comments from the public indicated that consumers thought “inert” meant “harmless”. Inert ingredients have not been defined as toxic or hazardous to humans, animals or the environment it should not be assumed inert means harmless. According to Cambridge Advance Learners Dictionary inert means: not reacting chemically with other substances. Hopefully that hasn’t totally scared you because inert ingredients play an important part in the effectiveness of pesticides. Inert ingredients may be used as a solvent which would allow the active ingredient to penetrate the outer surface of the plant or insect. In some instances, inert ingredients are added to extend the pesticide product’s shelf-life or to protect the pesticide from decomposition due to sunlight exposure. Some inert ingredients are added to provide at better application coverage or ease in the handling and mixing process. Federal law requires the total percentage of inert ingredients to be listed on the label but each individual inert ingredient does not need to be listed. It is perfectly legal to add more than one type of inert ingredient. Active ingredients are the part of the pesticide that repels, subdues, manages, kills, or controls the pest.
Q: Pesticide labels give a percentage of active and inert or other ingredients with percentage numbers. I understand the active part but what does inert or others mean?