How can the place where the real stone paint flows turn white on rainy days and how to deal with it?

Classification of masks 1. The new national institute of occupational safety and health (NIOSH) dust breathing protection standard (42CFR84 1995) was issued on June 8, 1995 (according to the classification of filter materials). N series: no time limit protection of non-oily suspended particles R series: eight-hour protection of non-oily suspended particles and sweat suspended particles P series: no time limit protection of non-oily suspended particles and sweat suspended particles Some particles have oily carriers, but these substances attached to electrostatic non-woven fabrics will reduce the electrical properties and make fine dust penetrate. Therefore, the filter material to prevent oil aerosol should undergo special electrostatic treatment to prevent fine dust. Therefore, each series is divided into three grades: 95%, 99% and% (namely, 95, 99 for short, and 100 for short), so * * * has nine categories of filter materials. II. EU EN 149 standard: FFP 1: minimum filtration effect 80% FFP2: minimum filtration effect 94% FFP3: minimum filtration effect 97% III, Australia AS 17 16 standard P 1: minimum filtration. Japanese MOL verification standard: ds 1: ds2: Minimum filtering effect 99% DS3: Minimum filtering effect. Chinese national standard GB6223-86UDC: There are more than four inspection standards, all of which are tested with micron granularity. The detection flow rate of EU standard is 95L/min, and that of American standard is 85L/min. Suspended particle size