In many states, for produce to be labeled 'organic', the producer must participate in a state certification program than ensures that only natural pesticides have been used on the produce.
One of the most commonly used naturally-occurring pesticides are the pyrethrins. The pyrethrins are natural insecticides extracted from chrysanthemums.
Certification programs usually allow the use of pyrethrums, rotenone, ryania, and sabadillia as insecticides on organic crops. Some of these natural pesticides, such as ryania, have not been well studied as to their toxicity.
In some cases, organically grown produce may contain more natural toxins than produce grown using conventional pest management. For example, apple juice from organically raised apples contains more patulin, a probable carcinogen, than conventionally raised apples.(Jukes TH. Organic apple juice no antidote for alar. J Am Dietetic Assoc 1990;90(3):371.)
With respect to environmental impact, there is evidence that a mixture of organic and conventional pesticides may be more effective with less harmful impact on the environment than purely organic regimes.(Kovach et al )
Some Very Informative Internal Links that Pertain to Pesticides in Farming and Gardening:
Some Very Informative External Links that Pertain to Pesticides in Farming and Gardening:
Prepared Summer 1997 by Bernadene Magnuson, Ph.D.
University of Idaho, Dept. of Food Science and Toxicology - EXTOXNET FAQ Team.