In this subtitle the following words have the meanings indicated. “Agricultural liming materials” means any substance that contains calcium and magnesium in condition and quantity suitable for use in neutralizing soil acidity, or that is used as an ingredient or reagent in the preparation of any fungicide or insecticide. “Distributor” means a person who imports, manufactures, produces, mixes, exchanges, sells, offers for sale, consigns, furnishes, provides, or supplies agricultural liming material or gypsum as part of a commercial enterprise. “Gypsum” means any product that consists chiefly of calcium sulfate and is intended for use for agricultural purposes. “Registrant” means any person who registers any agricultural liming material or gypsum pursuant to the provisions of this subtitle.