color change mask / sanitary mask

The importance of using the mask is increasing because of the MERSC or fine dust. But if you put the mask, you can’t feel assured. You can use the mask more effectively when you know about the mask. Generally the mask’s hours of use is within 10 hours. If you use the mask more than 10 hours, the effect of the mask is decreasing and if you put the mask continuously, it have danger of breeding of the virus and it can curse the eczema or rash. This mask change the color when the mask is polluted by virus or other thing what can curse the pollution. So someone, who use this mask, can escape from the danger of the polluted mask.