Hi Steffie,
Maintenance of storage areas for ingredients (product contact packaging is an ingredient and/or a food contact surface, depending on whether it will go through a wash/sanitize step before use) and warehousing in general is in the provisions of 21 CFR 110.80.
The gist under which you will need to write your risk assessment:
All food manufacturing, including packaging and storage, shall be conducted under such conditions and controls as are necessary to minimize the potential for the growth of microorganisms, or for the contamination of food
Also included, even though it states "finished products" it applies to warehousing in general: 21 CFR 110.93
Storage and transportation of finished food shall be under conditions that will protect food against physical, chemical, and microbial contamination as well as against deterioration of the food and the container.
(7) Equipment, containers, and utensils used to convey, hold, or store raw materials, work-in-process, rework, or food shall be constructed, handled, and maintained during manufacturing or storage in a manner that protects against contamination.
I would hold outside warehouses that are storing packaging materials for you to the sanitary transport requirements. In that the warehouse should be:
- Protected from excess dust, moisture, or other elements that could cause contamination
- Protected from conditions that will deteriorate the materials
- Free from pests and vermin
- Secure to prevent intentional adulteration (food defense)