Put 1 tablespoon of baking soda in 1 quart of warm water: University of Georgia Extension says scrub refrigerator door seals, then test them with a $1 bill

Your refrigerator door may appear clean, but the rubber around it can collect crumbs, grime, and residue. That seal, known as a gasket, does an important job: it helps keep the refrigerator door closed tightly. In its March 2022 Healthy Indoor Environments newsletter, the University of Georgia Extension recommended mixing 1 tablespoon of baking soda with 1 quart of warm water, scrubbing the gasket with an old toothbrush, and testing the seal with a $1 bill. It's a simple household chore, but it helps to know the facts about refrigerator gaskets.

Why that rubber gasket is important

A refrigerator works by keeping heat out of its cold compartments. The door gasket is part of the barrier that helps make this possible. A 2017 study in the International Journal of Refrigeration, ‘An experimental and numerical study of refrigerator heat leakage at the gasket region,’ by Feng Gao, Shervin Shoai Naini, John Wagner and Richard Miller, examined heat leakage in the area surrounding a refrigerator door gasket using both experimental and numerical methods. In their test setup, the researchers found that the gasket surface accounted for 17 percent of the total heat leak in the fresh-food compartment and 14 percent in the freezer compartment. Those numbers were from the experimental conditions in the researchers’ refrigerator. They should not be treated as a universal percentage for every refrigerator of every home, but the study shows why the gasket is more than a decorative strip of rubber. It is part of the fridge’s thermal system.

UGA's baking soda method is simple

The extension does not recommend any special cleaner or expensive equipment. The newsletter says to make a solution of 1 tablespoon baking soda and 1 quart warm water. It then suggests scrubbing the refrigerator gasket with an old toothbrush. After cleaning, it says to rinse the gasket with clean water and be sure to wipe away all the baking soda solution. A toothbrush makes sense because the gasket has folds and narrow areas that are hard to clean with a larger cloth.

The $1 bill test takes seconds

Cleaning the gasket is a good first step. From there, it's worth seeing if the seal is sealing tightly. The method is simple: close the refrigerator door on a dollar bill so that it's trapped between the door and the frame, then try to pull it out. If the dollar slips out easily, the gasket is not sealing tightly, says the University of Georgia Extension. This quick test gives you a reason to look more closely at the seal, but it won't measure the energy consumption of the refrigerator or tell you exactly how much heat is entering the compartment.

A gasket can affect refrigerator efficiency

A 2021 study, 'A review of refrigerator gasket: Development trend, heat and mass transfer characteristics, structure and material optimization,' by Guoqiang Liu, Gang Yan and Jianlin Yu for Renewable and Sustainable Energy Reviews, explains that the gasket is a crucial part of the refrigerator. This paper explores how the sealing and insulating capabilities of the gasket affect the performance and efficiency of the refrigerator. This doesn't mean that all dirty gaskets will necessarily raise your electricity bills. Neither does failure of the dollar bill test indicate that your refrigerator should be replaced right away; instead, it gives you a useful maintenance clue.

What to do if the bill slides out

If the dollar comes out too easily, begin with the most straightforward option: see if there is any dirt or other substance blocking the proper seal of the gasket and the door. Cleaning the gasket is the first step UGA recommends. After this is done, run the test again. If the door still fails the test, the gasket needs further inspection.

A small check for a commonly ignored part

UGA's tip is helpful because it makes a little-known bit of refrigerator maintenance into a quick check anyone can do. Research also supports the more general point that the gasket is a meaningful contributor to refrigerator heat transfer and performance. These are basic maintenance tools and are not substitutes for professional appliance testing when a refrigerator has a persistent sealing or cooling problem.