A person who owns or operates a plant shall protect supplies of parchment liners, wrappers, and other packaging material against dust, mold, and other possible contamination and do each of the following:

  (a) Prior to use, completely immerse parchment liners or bulk butter packages in a boiling salt solution within a stainless steel or other equally noncorrosive material for not less than 30 minutes.

  (b) Ensure that the solution described in subdivision (a) consists of at least 15 pounds of salt for every 85 pounds of water and is strengthened or changed as frequently as necessary to keep the solution full strength and in good condition.

  (c) Treat or handle liners such as polyethylene and each lined butter container in such a manner as to prevent contamination of the liner prior to filling.

  (d) Print and package consumer size containers of butter under sanitary conditions.

  (e) Legibly mark commercial bulk shipping containers with the name of the product, net weight, name and address of manufacturer, processor or distributor, or an assigned plant identification number or any other identification that the department may require.

  (f) Mark packages of plastic or frozen cream with the percent of milkfat.

  (g) Except as provided in subdivisions (i) through (k), keep all products under refrigeration at temperatures of 45°F (4.7°C) or lower after packaging and until ready for shipment.

  (h) Ensure that the products are not placed directly on floors or exposed to foreign odors or conditions such as drippage due to condensation which might cause package or product damage.

  (i) If plastic cream or frozen cream is to be quick-frozen, place the product in quick freezer rooms immediately after packaging, and ensure rapid and complete freezing within 24 hours by doing all of the following:

  (i) Pile or space the packages in a manner that allows air to freely circulate among and around the packages.

  (ii) Maintain the rooms at -10°F (-23°C) or lower.

  (iii) Equip each room to provide sufficient high-velocity air circulation for rapid freezing.

  (iv) After the products have been completely frozen, retain them in the quick freezer or transfer them to a freezer storage room for continued storage.

  (j) Maintain each freezer storage room at a temperature of 0°F (-18°C) or lower and ensure each freezer storage room has adequate air circulation.

  (k) Place butter intended to be held more than 30 days in a freezer storage room immediately after packaging, and if that butter is not frozen before being placed in the freezer, arrange each unfrozen butter package in a manner that permits rapid freezing, and keep each package in that arrangement until frozen.