Sunlight and circulating air keep mildew away. Unfortunately, a safe does not have either. Safes are dark, tight-seamed, secure boxes that do not allow light to enter or air to flow. Many homeowners store valuable items in safes, including documents, money and deeds, which have the potential to become mildew targets. Mildew stains and gives items a musty odor. Several remedies are available to keep mildew at bay.
Place plain white chalk in the safe to absorb moisture. If the chalk is in a cardboard box, open the lid and leave the chalk in the box. If the chalk is in a plastic container, remove the chalk, wrap it in a paper towel, and secure it with a rubber band to keep chalk residue off the interior of the safe. Replace the chalk every five to six months.
Open a box of fresh baking soda and place it into the safe. Baking soda absorbs dampness and helps deodorize musty smells. Remove and replace the baking soda every four to six months.
Wipe excess dust off two or three charcoal briquettes. Place the charcoal on a piece of fabric, gather the ends, and secure them in place with a string or ribbon. Leave the charcoal briquette sachet in the safe. Replace the charcoal every six months.
Fill a jar or cup with cat litter and place the cat litter in the safe. Cat litter absorbs moisture and helps prevent mildew growth. Remove and replace the cat litter every month.
Place silica gel packets in the safe to control moisture. Silica gel is a drying agent that will absorb dampness and prevent mildew growth. Replace the silica gel packets as often as directed by the manufacturer.
Store a commercially available calcium chloride-based drying agent in the safe to attract moisture. Typically, drying agents come in their own containers and require peeling off a protective lid. Follow the manufacturer's directions to determine the frequency of replacement.