This plastic foundation insert will out-perform all other plastic frames or inserts currently on the market. This is because it is made from polypropylene, which is approved by the FDA for food contact. It is also considered by the Environment Protection Agency (EPA) to be the safer choice than some other plastics. This plastic is BPA free. For the best results dip the inserts with 100% Australian Bee Wax. We also recommend the use of this product in your honey supers only. This is because it will stop blow outs or breakages of wax foundation frames when extracting. The plastic insert gives you much more strength.