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 we have dipped the inserts with 100% Australian Bee Wax. It has an average coating of around 70g of bees wax. This will take away what small odour this product gives off, also gives the bees a head start in drawing of the comb. 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.