(a) 
         When applied to growing crops, in accordance with good agricultural practice, the following pesticide chemicals are exempt from the requirement of a tolerance:
     
    
    
    
    
        
        (4) 
         Rotenone or derris or cube roots.
     
    
    
        
        (b) 
         These pesticides are not exempted from the requirement of a tolerance when applied to a crop at the time of or after harvest.
     
    
        
            Code of Federal Regulations
        
        [75 FR 60245, Sept. 29, 2010]