2. Batteries
Batteries usually have an expiration date printed on the packaging or on the battery itself. Even if they have not been used, old batteries usually do not hold as much charge as new ones. Alkaline (disposable) batteries can last up to 10 years (although some manufacturers say up to 5 years), rechargeable batteries usually need to be replaced after 5 years. Lithium can be stored up to 10 years. But salt batteries can last only a couple of years.

3. Mattresses
Most are made with a shelf life of 10 years, but the exact life depends on what the mattress is made of. You can check the information with the manufacturer or the seller.

4. Bleach
Bleach loses its effectiveness over time. Various sources give it a shelf life of 3, 6, or 12 months, but one easy way to determine this is to smell it: if the smell is faint or absent, it's probably time to buy a new bottle.

5. Hand warmers
If you use disposable hand warmers and store them from winter to winter, you should know that the old ones will not keep your hands warm when you need them. Hot Hands says their heating pads expire in 4 years.