Is there a better option than baking soda for deodorizing the refrigerator?
We’ve found that baking soda is only moderately effective as an odor eliminator. It works by changing the structure of acidic molecules that it comes in contact with—which may make some stinky acidic molecules smell better but might simply make them smell different (but still bad). Furthermore, while most foods are at least slightly acidic, not all are. A little research informed us that so-called activated charcoal (a substance used in air filters, to clean the water in fish tanks, and to purify water) might be more effective. Because it is pure carbon, which absorbs almost all organic molecules, activated charcoal should potentially absorb—and thus remove from the air—almost all smelly molecules that it encounters. And because it’s very porous, it has lots of surface area for smells to “stick” to.
To evaluate its effectiveness, we placed 1 cup of baking soda in an open container in one mini refrigerator and 1 cup of activated charcoal pellets in an identical fridge. During the course of a month, we placed various smelly items, including chopped onions, kimchi, Parmesan, and canned tuna, in each refrigerator and asked testers to evaluate how they compared. Throughout the testing, they agreed that the refrigerator with activated charcoal was significantly less stinky than the refrigerator with baking soda.
Activated charcoal can be found at pet and aquarium supply stores. For a full-size refrigerator, we recommend using 2 cups placed in an open container in the back of the fridge near an air vent. How often the charcoal needs to be replaced will vary depending on refrigerator size and contents, but based on our results, we predict that it will last at least one month and possibly much longer.