This air dry clay kit is made of quality-assured borax-free raw materials. Non-toxic, brightly-colored, smooth feel, non-stick hands, ultra-light and resilient, and easy to handle. Strictly comply with ASTM & CPSIA standards and requirements. The modeling clay is safe and gentle in the environment. Recommended for use on a surface covered with wax paper, parchment paper, or ceramic tile. Not recommended for use on brown paper table covers, wood rollers, etc., or they will stick to them. Play without worrying, and let the fun begin!