Harvest Green uses Dunlop latex and cotton. Harvest Green Mattresses only uses natural GOLS Certified organic latex rubber foam, derived directly from a sustainably harvested source. Our organic cotton is the most breathable, coolest, softest materials available. It also naturally wicks away moisture. All of these attributes make our top covers luxurious and one of the best sleep surfaces available. Our Cotton is also certified by OEKO-TEX to have no harmful substances such as allergenic dyes, pesticides, chlorinated phenols, heavy metals, formaldehyde, and chloro-organic carriers.