Section 180.1130 - N-(n-octyl)-2-pyrrolidone and N-(n-dodecyl)-2-pyrrolidone; exemptions from the requirement of a tolerance(a)N -(n-octyl)-2-pyrrolidone and N-(n-dodecyl)-2-pyrrolidone are exempt from the requirement of a tolerance when used as solvents in cotton defoliant formulations containing thidiazuron and diuron as active ingredients.(b)N -(n-octyl)-2-pyrrolidone is exempt from the requirement of a tolerance when used as a solvent in formulations containing pyraflufen-ethyl as an active ingredient at a concentration not to exceed 20% by weight.(c)N -(n-Octyl)-2-pyrrolidone is exempt from the requirement of a tolerance when used as a solvent in formulations containing prothioconazole as an active ingredient at a concentration not to exceed 15% by weight. 79 FR 10682 , Feb. 26, 2014, as amended at 88 FR 47778 , July 25, 2023 As amended at 88 FR 47778 , 7/25/2023