In article , Franz Heymann
writes

(a) On what grounds are nicotine classified as "not organic"?
Nicotine is a dangerous poison not permitted for use by commercial
growers of organic produce and not recommended for use by recreational
gardeners wishing to follow organic methods. The fact that nicotine and
many other banned substances originate from plant or animal material
does not make them suitable for use in organic growing.
(b) How is pyrethrum classified?
(c) An organic afficionado claimed in this ng (this thread?) that Bordeaux
mixture was classified as organic.
Both Pyrethrum and Bordeaux Mixture are listed as not suitable for use
in organic horticulture. Along with other substances, they are listed as
permissible to be used by growers in the conversion period to organic
growing. Produce grown with their use cannot be sold as organic.
--
Alan & Joan Gould - North Lincs.