First, put the mask in a sink with cold to lukewarm water. Swing the mask back and forth in the water 3-5 times. Then you can hang them up to dry. When washing, avoid rubbing and wringing the mask so you don't damage the internal filter. The mask should therefore not be washed in the washing machine. Change the mask after 20 washes. We recommend washing the mask at least once a week (depending on usage).