Our EVOLON fabric has a 1 micron filtration which gives you the highest protection in bedding encasements on the market. EVOLUTION's Sleep Safe ZipCover features EVOLON® fabric. The European Centre for Allergy Research Foundation (ECARF) awarded the coveted Seal of Quality to EVOLON® in providing the perfect physical layer to protect against Bed Bugs, Dust Mites & Allergens. German engineered and medically approved for anti-mite protection. This patented fabric is created from a solvent and binder-free process using only stable raw materials that are environmentally safe. "EVOLON®'s ability to offer a natural and physical barrier that is 100% safe, comfortable and effective makes it the method of mite-proof protection recommended by medical specialists. EVOLON® fabric in EVOLUTION Sleep Safe ZipCovers mite-proof mattress and pillow encasings bridge the gap between performance and comfort, representing a significant leap for dust-mite sufferers everywhere." EVOLON®'s award of the ECARF Seal was based on its ability to meet the stringent testing and validation criteria of various independent institutes. EVOLON® has also been granted the Oeko-Tex Mark (Standard 100, Product Class 1) which certifies it is free of harmful substances and suitable for contact with baby skin. Its filtering barrier comes from a dense compact fiber structure that's breathable yet strong. Because the fabric (not chemicals) protects you, there's no stiff rustle sound. Washing doesn't remove its effectiveness and only makes the fabric softer. Construction is controlled at our American plant, employing highly skilled US Workers. Our products come with a 10 year guarantee. For best protection, encase all pillows, mattresses and box springs. Use ELF for Bed Bugs & Dust Mite Spray to naturally eliminate insects.