(1) To flour ground for the wheat producer whereby the miller is paid in wheat or feed for the grinding service rendered, except in so far as such a mill may manufacture toll wheat into flour and sell or offer for sale such flour, whereupon this chapter shall be applicable;

(2) To farmers in exchanging their wheat for flour or having it ground into flour and disposing of it for their own use or the use of farm labor on their farms;

(3) To flour sold to bakers or other commercial secondary processors, providing the purchaser furnishes to the seller an approved certificate of intent to use such flour solely in the production of enriched flour or enriched bread as herein defined or in the manufacture of legitimate products not covered by the provisions of this chapter; or

(4) To flour or bread which is made from the entire wheat with no parts of the wheat removed from the mixture. Flour or bread containing mixtures of the whole wheat berry and white flour or mixtures of various portions of the wheat berry shall have a vitamin and mineral potency at least equal to enriched flour or enriched bread as described in §§ 39-27-10 and 39-27-30.