Nonsynthetic substances prohibited for use in organic crop production.

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]