By joy from Howell, MI
Baking powder and baking soda can still be used beyond their expired date.
Go to a search engine and find out how to test your baking powder and baking soda. You'll find baking websites that will show you how to test those two leveling ingredients.
Since baking powder is basically just baking soda with some extra leavening and reacting agents in it for cooking, when it "expires" for your baking uses, you can still use it as baking soda (sodium bicarbonate).
It can be used as a cleaning agent for scrubbing stains in sinks and on countertops.
It can be kept near the stove for smothering small grease fires on your range.
It is good for a first aid for animal urine on a carpet or wood flooring, not only to absorb some of the urine, but to help neutralize the acidity and minimize damage to nice floor coverings.
It can also be used to raise the total alkalinity in a spa or hot tub.
It might still be effective as an odor absorbent in your refrigerator.
I can't think of any other uses, but there are probably dozens of other uses for baking soda around the home that have been compiled over the years.
I found the website that shows how to test baking powder and baking soda.
Use it between your toes to keep feet dry to prevent athlete's foot; my father and brother always did this over 50 years ago.