Continuing to use the filter cartridge that has reached the end of its service life can produce white powder, which can attach to the floor or wall surfaces of the room, as well as electrical appliances, furnitures and the like. Replace the filter cartridge with a new one as soon as possible when something like this occurs. The white powder is crystallization of calcium carbonate found in tap water, and is harmless to humans. Wipe it off with a cloth.
The filter cartridge is a consumable part. Ordinarily, the cartridge is replaced in about six months as a rough standard (assuming one tankful of water is supplied each day). The service life of the cartridge may be shortened depending on the hardness of the supplied water used.