The Cone 5 Stoneware reactive glazes are all lead-free and dinnerware safe. They are formulated to produce interesting and beautiful effects after firing. Their final appearance can be affected by different clays and also the presence of layering of other glazes. Due to the sensitive nature of these glazes, Cone 5 specifically is our recommended firing temperature. Dinnerware safe. Contains no lead or cadmium ingredients. Certified AP Non-Toxic and conforms to ASTM D-4236.