7 CFR § 205.602 - Nonsynthetic substances prohibited for use in organic crop production.
(a) Ash from manure burning.
(c) Calcium chloride, brine process is natural and prohibited for use except as a foliar spray to treat a physiological disorder associated with calcium uptake.
(d) Lead salts.
(e) Potassium chloride - unless derived from a mined source and applied in a manner that minimizes chloride accumulation in the soil.
(f) Rotenone (CAS # 83-79-4).
(g) Sodium fluoaluminate (mined).
(j) Tobacco dust (nicotine sulfate).