Pure silver is a natural bactericide. When the Bluemagicball is in the washing machine, silver ions are released into the water and distributed into your laundry. The washed laundry remains impregnated with silver for approximately 10 weeks and even helps prevent body odour for up to 2 days. Tests have shown that the bioactive fibres are safe for the skin and can be helpful in the prevention of skin infections. You no longer need to wash on a hot wash for hygienically clean laundry. The colour indicator on the ball will change from red to pale blue when it needs replacing.