What's Inside Matters Organic Rubber Latex Our natural latex is sustainably harvested from tropical rubber trees and manufactured into cores in the USA, and has been independently tested and certified to Oeko-Tex Standard 100 (contains no harmful substances) as well as tested for harmful emissions through GREENGUARD. Natural FR Solution Our mattresses pass all federal flame requirements naturally. Our chemically safe FR solution is sand. We impregnate rayon/cotton blend fabric with natural silica. It's so natural, it's passed the GREENGUARD GOLD emissions test. This test considers safety factors to account for sensitive individuals. Organic Cotton Our Signature Ergovea cover is made using certified organic cotton and has been independatly tested and certified by Okeo-Tex Standard 100. We elected to add a 2% Lycra to the cover to allow for supreme movement and durability. We use a gram weight of 460 (which is the highest available) to give the fabric its luxurious feel and movement.