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, Soft and Breathable Provides a soft, non-sweaty and comfortable waterproof barrier (as compared to vinyl and rubber). Also blocks dust-mites and other allergens. 100% Cotton Fabric - Top and Bottom Layers