The Sea to Summit X-Bowl is a collapsible hybrid comprised of a rigid, cut-resistant base made of high temperature, food-grade nylon and walls made of food-grade flexible silicone, so they fold flat for compact packing. It is tough enough to handle chopping with its sturdy nylon base. The silicone sides can withstand temperatures of hot foods and nearby hot surfaces up to 300 degrees Fahrenheit. The sides are flexible, so pouring liquids is easy. When collapsed down flat, the X-Bowl fits snugly into the X-Plate for extra space savings when packed. All X Series products are BPA free.