Section 174A. No person shall pack for sale, sell, offer or expose for sale in this commonwealth, except in containers of net avoirdupois weights of five, ten, twenty-five, fifty and one hundred pounds, and multiples of one hundred pounds, any of the following commodities:— wheat flour, self-rising wheat flour, phosphated wheat flour, bromated flour, enriched flour, enriched self-rising flour, enriched bromated flour, corn flour, corn meals, hominy and hominy grits; provided, that this section shall not apply to (a) the retailing of flours, meals, hominy and hominy grits direct to the consumer from bulk stock, or (b) the sale of flours and meals to commercial bakers or blenders or for export in containers of more than one hundred pounds, or (c) flours, meals, hominy and hominy grits packed in containers the net contents of which are less than three pounds, or (d) the exchange of wheat for flour by mills grinding for toll. Whoever violates any provision of this section shall be punished by a fine of not less than twenty-five nor more than five hundred dollars or shall be subject to a civil citation as provided in section 29A of chapter 98.