While freezing foods in these types of containers does not present a safety problem, they can affect the quality of the food. Packaging materials must be moisture/vapor resistant; durable and leak-proof; not become brittle and crack at low temperatures; resistant to oil, grease or water; protect foods from absorption of off-flavors or odors; easy to seal and easy to mark. Good freezing materials include rigid containers made of aluminum, glass, plastic, tin or heavily waxed cardboard; bags and sheets of moisture/vapor resistant wraps and laminated papers made especially for freezing.

Do not re-heat or cook foods in these used plastic containers or allow plastic wrapping to touch the food as it cooks or heats. The gasses given off by these materials can lend an off-flavor or contaminate the food with chemicals which have dissolved and migrated from the container or plastic-type wrap into the food during re-heating or cooking. Instead, remove the food from the plastic container and place it in an oven- or microwave-safe bowl, pan or dish and cover with the top that came with that container or cover lightly with paper towels if microvaving, to help retain the food's natural moisture.