Hypoallergenic, Fluid Resistant, Particle Filtration to .01 Micron, 500/case (10 bags of 50). - For superior comfort and protection, the hypoallergenic, high breathability, fluid resistant AlphaGuard Mask exhibits an excellent water vapor transmission rate and particle filtration to 0.1 micron. The mask is designed for use in cleanroom environments up to Class 100 (ISO Class 5). Soft, latex-free, non-irritating knit ear loops are ultrasonically welded to the mask.