They can be grouped into chemical families based on their structure and mode of action in the pest. Important chemical families of fungicides and insecticides are presented here. This group includes both contact and systemic insecticides. They are not as persistent as chlorinated hydrocarbon products but tend to be more toxic to applicators and wildlife. The organophosphate insecticides are nerve poisons and have been involved in most serious human pesticide poisonings.
Carbamates tend to be quite soluble in water and some are systemic in plants.
They are typically used at rates of active ingredient that are several times lower than organophosphate and carbamate insecticides. They generally exhibit low mammalian toxicity but are highly toxic to fish and other cold blooded organisms. Several other insecticide families are currently being introduced. The organic sulfur fungicides are all protectants. They are systemic in the plant and have eradicant activity.