(1) The department shall examine the commercial fertilizer product registration application form and labels for conformance with the requirements of this chapter. If the application and appropriate labels are in proper form and contain the required information, the particular commercial fertilizer products shall be registered by the department and a certificate of registration shall be issued to the applicant.
(2) In reviewing the commercial fertilizer product registration application, the department may consider experimental data, manufacturers' evaluations, data from agricultural experiment stations, product review evaluations, or other authoritative sources to substantiate labeling claims. The data shall be from statistically designed and analyzed trials representative of the soil, crops, and climatic conditions found in the northwestern area of the United States.
(3) In determining whether approval of a labeling statement or guarantee of an ingredient is appropriate, the department may require the submission of a written statement describing the methodology of laboratory analysis utilized, the source of the ingredient material, and any reference material relied upon to support the label statement or guarantee of ingredient.
(4) Before registering a waste-derived fertilizer or micronutrient fertilizer, the department shall obtain written approval from the department of ecology as provided in RCW
15.54.820. Once a waste-derived fertilizer or micronutrient fertilizer has been approved by the department of ecology, its subsequent use in another product during that registration cycle shall not require department of ecology review. This subsection shall apply to new and renewal registration applications for periods beginning July 1, 1999, and thereafter.