Instead of using toxic chemicals, the foam in our kids mattress is wrapped in a specially-made tubular knitted fabric (often referred to as an FR sock) that is inherently flame retardant. Additionally, our fire barrier has been tested and certified by OEKO-TEX , which tests for harmful substances in textiles. Essentially, we rely on the properties of the materials themselves, instead of harmful chemicals, to achieve fire retardancy. Because chemicals have no place in a child's bed!