@Slashvi 11 December 2021 more from that month

WHY is limescale in the kettle not considered harmful to humans? If a person swallows some scale, he or she will only get an unpleasant feeling in the mouth. Limescale is mainly calcium and magnesium salts, physiologically inactive due to their insolubility. However, these layers do not conduct heat well: settling on the heater, they increase the boiling time of water and are harmful only to the kettle itself.