The reddish or pinkish substance observed within ice makers is commonly caused by a waterborne bacterium called Serratia marcescens. This bacterium thrives in moist environments and produces a red pigment called prodigiosin. Its presence is most noticeable in areas with standing water, such as the reservoir or drip tray of an ice maker. This discoloration is not typically harmful, but its presence indicates the need for cleaning.
Understanding the origin and nature of this discoloration is important for maintaining appliance hygiene and preventing further bacterial growth. While Serratia marcescens is generally considered non-pathogenic for healthy individuals, in rare cases it can cause infections, particularly in immunocompromised individuals. Regular cleaning not only removes the discoloration but also helps ensure the production of clean and safe ice.