Naturepedic The No-Compromise Organic Cotton Classic is simply the healthiest crib mattress available. It is waterproof, firm and eliminates potentially harmful chemicals from your child?s crib. It will provide your child with a more natural, healthy and comfortable sleep environment. n]Waterproof Organic Cotton CoverFeatures a luxurious organic cotton fabric with a clear 100% polyethylene food-grade waterproof coating. Non-allergenic and easy-to-clean.