What are they?
Pesticides are substances used to control organisms that are considered pests, such as insects, bacteria, fungi, plants and animals. Pesticides are designed to deter or harm the organisms they target, but they often have negative impacts on other organisms as well, including humans.
Many pesticides that are in widespread use are organic compounds, and these are often grouped into categories like organochlorines, organophosphates and carbamates. Organochlorines include the well-known pesticide DDT (dichlorodiphenyltrichloroethane), which was widely used until the 1960s and 1970s, when its use was phased out.
Chemical compounds can be organic or inorganic. This depends on what elements they are made of. Elements are substances that cannot be broken down into simpler substances. There are 118 known chemical elements and all matter on earth is made up of some combination of them.
Organic compounds are substances made up mostly of hydrogen and carbon (or hydrocarbon). Inorganic compounds do not contain hydrocarbon, and most do not contain carbon.