It is important to note that not all non-synthetic materials (natural) are allowable, nor are all synthetic materials excluded from use in organic production. Notable exceptions include insecticidal soap, a synthetic compound that can be used in pest control, and tobacco dust, a natural product that is not permitted. The Organic Materials Review Institute (OMRI) evaluates materials for use in organic agriculture and publishes their findings in the form of lists of allowable and prohibited inputs. The certifying agency, however, makes the final decision regarding what products can or cannot be used on the organic farm
