No doubt this could be a problem with chemicals leaching into the food. I know Ziplock Zip and Steam bags contain no extra chemicals for that reason. the bag is made from PE PET period. Plus, I am terrible at sealing the regular zip locks, but a pro at using the ones that are truly self sealing. Zip and steam melts at 280F, so no danger of the lobster meat or Truffles escaping from the bag.