Iowa Code § 206.3
The examination of pesticides and those products to which pesticides have been applied for the content of pesticide residues shall be made under the direction of the secretary, or the secretary's authorized representative, for the purpose of determining whether they comply with the requirements of this chapter and rules adopted under this chapter. If it shall appear from such examination that a pesticide fails to comply with the provisions of this chapter, and the secretary, or the secretary's authorized representative, contemplates instituting criminal proceedings against any person, the secretary or representative shall cause notice to be given to such person. Any person so notified shall be given an opportunity to present the person's views, either orally or in writing, with regard to such contemplated proceedings and if thereafter in the opinion of the secretary, or authorized representative, it shall appear that the provisions of the chapter have been violated by such person, then the secretary or authorized representative may refer the facts to the county attorney for the county in which the violation shall have occurred with a copy of the results of the analysis or the examination of such article; provided, however, that nothing in this chapter shall be construed as requiring the secretary or representative to report for prosecution or for the institution of proceedings in minor violations of the chapter whenever the secretary or representative believes that the public interests will be best served by a suitable notice of warning in writing.
Iowa Code § 206.3