PeachSkinSheets are STANDARD 100 by OEKO-TEX® certified (Number 20.HCN.29518) so you can be sure our SMART Fabric keeps you and your family safe from harmful substances. PeachSkinSheets are made of a High-end Athletic Grade poly fiber that is moisture wicking and also breathable. Athletic grade poly fiber actually has several advantages over cotton since it is specifically engineered for comfort. It is more breathable than cotton, doesn’t shrink, features wrinkle release out of the dryer, and wicks away sweat like workout wear rather then absorbing it. PeachSkinSheets are also pesticide-free, unlike some non-organic cotton sheets. The best part is that PeachSkinSheets have the softness level of 1500 Thread Count sheets without being extremely hot, so you get the best of both worlds. Our Athletic Grade fabric is also hypoallergenic, naturally antimicrobial and great for sensitive skin.