How does novolog insulin storage work?

Refrigerator/Room tp: Unopened vials /pens can be stored in refrigerator till expiration date on the product. Once removed from the refrigerator, opened/unopened vials can be stored at room temp or refrigerator and discard after 28 days, opened pens/cartridges should be stored at room temp discard in 14 days regardless. For external pump reservoir discard in 6 days. Novolog should not be used if it had been frozen.