(a) Agricultural liming materials sold, offered or exposed for sale in the Commonwealth shall have affixed to each package in a conspicuous manner on the outside thereof a plainly printed, stamped or otherwise marked label or tag, or, in the case of bulk sales, a delivery slip setting forth at least the following information:

(b) No information or statement shall appear on any package, label, delivery slip or advertising matter which is false or misleading to the purchaser as to the quality, analysis, type or composition of the agricultural liming material.

(c) If any material is added to any agricultural liming material, subsequent to packaging, labeling or loading thereof and before delivery to the consumer, a plainly marked notice to that effect shall be affixed by the vendor to the package or delivery slip to identify the kind and degree of such added material.

(d) At every site from which agricultural liming materials are delivered in bulk and at every place where consumer orders for bulk deliveries are placed, there shall be conspicuously posted a copy of the delivery slip required by this section for each brand of material.

(e) The secretary may, after a public hearing, require by regulation thereafter that the minimum percentage of calcium oxide and magnesium oxide shall be expressed in the following form:

The secretary may not impose such regulatory standards if they conflict with labeling requirements of other states and if they would thereby constitute an economic hardship on the industry due to dual labeling requirements. The effective date of said regulation shall not be less than 18 months following the adoption of regulations. For a period of two years following the effective date of the regulations the equivalent of calcium and magnesium may also be shown in the form of calcium oxide and magnesium oxide.