I didn't have any plastic lids, so I used a thick piece of plastic cut from a freezer bag to place between my metal lid and the jar. Last night my one of my teenagers wanted to put some in a jar to keep in her bathroom and use on her Acne so I told her to help herself. UNFORTUNATELY, she misplaced the piece of plastic and just put the metal lid on, and also used a metal lid on her own supply. So is it wasted? It still looks and tastes the same. Can I just say "grrrrrrrr."