Section 180.130 - Hydrogen Cyanide; tolerances for residues(a)General. A tolerance for residues of the insecticide hydrogen cyanide from postharvest fumigation as a result of application of sodium cyanide is established as follows: 50 parts per million in or on Fruit, citrus.(b)Section 18 emergency exemptions. [Reserved](c)Tolerances with regional registrations. [Reserved](d)Indirect or inadvertent residues. [Reserved]64 FR 39077, July 21, 1999