Yellow Residue on Domestic Refrigerators

Sodium Chromate

• Sodium chromate is a powdery chemical compound that dissolves readily in water and other liquids. It is found in many refrigerators built for recreational vehicles and mobile homes. These refrigerators are often designed to operate with several energy sources, including electricity and propane. If yellow residue is found on an RV refrigerator, the entire appliance should be disconnected immediately and the residue should be tested for sodium chromate. Some RV refrigerators were recalled by manufacturers due to a defect that allowed flammable chemicals, including sodium chromate, to escape from the cooling system.

Ammonia

• Ammonia is another common chemical found in the coolant system of domestic refrigerators. Damaged or worn pipes can release liquid ammonia inside or beneath refrigerators. Ammonia releases a pungent odor, and its fumes can be toxic in high concentrations. A filtering mask and rubber gloves should be used to clean ammonia spills. Do not use other household cleaning chemicals to deal with an ammonia spill. Ammonia is highly reactive to compounds found in some cleaners, like bleach, and may release a toxic gas when mixed.

Mold

• Mold is a common cause of yellowing on the interior and exterior of household refrigerators. It is not as hazardous as toxic chemicals, like ammonia and sodium chromate, but it can pose a health risk to people with sensitive respiratory systems or fungal allergies. Mold is present in practically every home environment, so it is difficult to completely prevent it from growing on refrigerators. Regularly cleaning refrigerators and disposing of food spills promptly will help keep mold in check. Mold can be removed by applying a strong detergent to affected areas.

Environmental Causes

• Most yellow residue and discoloration on refrigerators is from environmental stress and paint corrosion. Appliances coated with white paint gradually turn yellow over time. The discoloration is accelerated if the refrigerator is positioned close to a source of heat, like a radiator or oven. Insufficient light can also cause white appliances to yellow prematurely. Tobacco smoke will coat most surfaces, including walls and appliances, with a yellow residue. To prevent tobacco staining, increase the air circulation throughout the house or consume tobacco products outdoors.