Storing food in plastic bags that held newspapers, plastic trash bags or other similar plastic bags is specifically discouraged because these plastic bags are not made of food-grade material. Because these bags were not designed to hold food, it is possible that they are not compatible with food and chemicals from the plastic material can leach or migrate into the food. This would be more of a problem with acidic or liquid food products. It’s best to simply recycle these bags. Interesting, food safety experts would also discourage reuse of any type of plastic bags such as bread bags or food storage bags. This is because it’s nearly impossible to clean a plastic bag completely. (I know that I am often guilty of forgetting this simple food safety rule. When I use up the end of a sandwich loaf, I often use the bag to carry the next day’s lunch.) Thanks to Gayle Rose Martinez for this question!