There is a widespread belief that organic agriculture does not use pesticides that are toxic to humans. This belief is incorrect.
Organic agriculture was founded on the sustainability of the earth to produce food, and on the bond between farmers and that earth. Most food production today depends on the continuous addition of energy-intensive fertilizers and other external materials to farm soil to keep it productive. Organic agriculture aims at keeping farm soil and farming as sustainable as natural forests, for time immemorial. This is a valuable and laudable aim.
Unfortunately, the organic philosophy has become perverted by the meme that everything in nature is desirable, that everything made by people is evil. Nature is green in tooth and claw, not just red! There are natural plant toxins that can kill a horse in a single meal (e.g. the genus Senecio), fungal toxins that can kill a person with a single mouthful (especially in the genus Amanita), snakes, spiders, wasps and fish that produce lethal toxins to kill their prey or enemies...
Two nerve poisons are in particularly widespread use in organic agriculture as it is presently practised - pyrethrins and rotenone. Both, and others such as nicotine, are just as toxic to people as they are to pest insects. Arsenic, copper, lead and other elements are natural too; as I write, it has been found that some organic frozen vegetables from China contain large amounts of toxic thallium - perfectly natural and therefore organic.
Organic agriculture needs to add the sustainability of people to the sustainability of the earth. Only substances non-toxic to humans should be used to grow human food if it is to be truly safe. Permissible organic inputs should be based on GRAS, generally regarded as safe, rather than 'natural' as at present.
other notes on pesticides