The mask can be used for more than 2 years, and the filter is recommended to be replaced every 30 days. The frequent or severe haze area is subject to the situation (the filter becomes black or damaged, please replace it in time, recommended once every 2-4 days). The material of the mask is made of diving cloth. A slight taste is normal. You can take out the filter first and soak it in warm water for 15 minutes. The taste will slowly disappear. The principle of activated carbon of the filter cannot be washed.