Section 206.4 - Classification of licenses1. The secretary may classify or subclassify certifications or licenses to be issued under this chapter. Each classification shall be subject to separate testing procedures and requirements. However, no person shall be required to pay an additional license fee if such person desires to be licensed in one or all of the license classifications provided for by the secretary under the authority of this section.2. The secretary in promulgating rules under this chapter shall prescribe standards for the certification of applicators of pesticides. In determining these standards the secretary shall take into consideration standards of the United States environmental protection agency and is authorized to adopt by rule these standards.