Anyone else running into this problem? Purchasing powders from various sources with the seal under the screw on lid is not secure. I find that any gallon of milk has a far better tamper proof cap than powders do. Three cans of H4350...unscrew the metal cap and the 'film' seal is flopping up as you remove the lid. It leaves me with a less than happy feeling that this has never been opened before. I would like to see one of those plastic seals around the outside of the lid that if intact shows the lid has never been removed. I would like to know that what I am purchasing is indeed what is in the container.