The Food and Agriculture Organization of the United Nations has defined the term pesticide as:

Any substance or mixture of substances intended to prevent, destroy or control any pest, including, for example, vectors of human or animal diseases, as well as unwanted species of plants or animals causing harm or damage during or interfering with the process of production, treatment, storage, Transportation or marketing of foods, as well as agricultural products, timber and wood products, animal nutrients, or even materials that can be used to treat animals by controlling insects, arachnids, or any other pests that live either in or on the bodies of various bodies. The term also includes those substances which are intended to be used as plant growth regulators, to protect plant leaves, to dry them, or as an agent to loosen plant leaves or prevent premature dropping of fruits from their branches. The term is used to refer to any material used on crops, either before or after harvest, to protect the crop from spoilage during storage or transportation.