(a)(1) Vacuum fumigation as required in this subpart must be conducted in accordance with part 305 of this chapter.

(2) After cotton and covers have been vacuum fumigated they shall be so marked under the supervision of an inspector. Such material may thereafter be distributed, forwarded, or shipped without further plant quarantine entry restriction.

(3) Cotton and covers held by an importer for vacuum fumigation must be stored under conditions satisfactory to the inspector.

(4) Prompt vacuum fumigation of cotton and covers (other than high density cotton free of surface contamination) will be required at non-northern ports. Similar prompt vacuum fumigation will be required at Norfolk, Virginia, during the period June 15 to October 15 of each year, except for covers which have been used to contain only lint, linters, or waste, and the bales of which are compressed to a density of 28 or more pounds per cubic foot and are free of surface contamination.

(b) An inspector may authorize the substitution of processing, utilization, or other form of treatment for vacuum fumigation when in his opinion such other treatment, selected by him from administratively authorized procedures, will be effective in eliminating infestation of the pink bollworm.