Salt, Ferrous Sulfate, Copper Sulfate, Calcium Iodate, Monosodium Glutamate - in excess. Sugar - Sucrose, corn syrup, molasses, cane sugar. Low quality commercial dog biscuits and treats. Low quality dry food. Low quality canned food.
All plastics release some undetectable fumes, especially when heated.
This out-gassing means the fumes can pass into the foods that are served or stored in the bowl or container. Stainless steel or glass bowls are recommended. Fumes from all bathroom cleaners. Fumes from bleach. Fumes from dusting products.