There are a few problems with beeswax, given the very low supply and high demand the price of real beeswax is an order of magnitude greater than paraffin wax, so there is a very large incentive to at the very least mix in some paraffin. Also much of the beehive foundation sheets are made of adulterated wax. But even if you managed to find some real beeswax, given that bees are collecting pollen from many fields that have been treated with pesticide the harmful substances tend to accumulate in the beeswax and the concentration increases every year if not filtered correctly, and given how hard it is to filter it from fatty substance you might end up with some in the wax.