These mask are intended to be used for protection against solid and liquid aerosols in wood, cement, glass working, textile, mining and construction environments. They are extremely durable and have a soft and comfortable inner surface with an adjustable nose piece and secured head straps for a proper fit. There is a low breathing resistance for increased working comfort. ALL FFP3 masks are to be used in situations up to 20 times the Occupational Exposure Level (OEL). The exhalation valve reduces breathing resistance and provides greater comfort in hot and humid work conditions.