The following nonsynthetic substances may not be used in organic crop production:
- (a) Ash from manure burning.
- (b) Arsenic.
- (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).
- (h) Sodium nitrate—unless use is restricted to no more than 20% of the crop's total nitrogen requirement; use in spirulina production is unrestricted until October 21, 2005.
- (i) Strychnine.
- (j) Tobacco dust (nicotine sulfate).
[68 FR 61992, Oct. 31, 2003, as amended at 83 FR 66572, Dec. 27, 2018]