Glass bakeware need to be tempered and resistant to extreme temperatures. Glass is the recommended container material when microwaving food. All of our glass bakewares are made from high quality and sustainable glass and are free of bpa, lead and other harmful toxins that can get into food. We supply bulk thickened glass bakeware, their glass and sealing material is food grade and high quality. These glass bakeware come from high quality and thickened containers, making them microwave safe to use.