This 6 Inch 2-Stage Crib & Toddler Mattress has an Organic Cotton, water repellent, removable & machine washable. This 100% Breathable mattress not only helps regulate temperature by allowing air to pass through the entire mattress, but there are no VOC's, no off-gassing (that chemical smell when you open a mattress with foam), and no toxic emissions. It's designed for extra firm infant support, and a comfortable plush side for your growing toddler. All materials used are eco-friendly, hypoallergenic, and breathable. This mattress is GreenGuard Gold Certified.