(a) Whenever the Secretary finds, on the basis of the Committee's recommendation or other information, that limiting the total quantity of a class of oil of any crop that handlers may purchase from or handle on behalf of producers during a marketing year, would tend to effectuate the declared policy of the act, the Secretary shall establish the salable quantity for that oil.

The salable quantity shall be prorated among producers by applying an allotment percentage to each producer's allotment base for that class of oil. The allotment percentage shall be established for each class of oil by dividing the salable quantity by the total of all producers' allotment bases for the same class of oil.

(b) When an allotment percentage for a class of oil is established for any marketing year, no handler shall purchase from or handle on behalf of producers any oil of that class during such year unless: