If left unchecked, rust can corrode the interior of your toaster oven. The concern is not that the rust will infect your food. AZ Rust explains that even though rust is not pleasant to eat or drink, consuming it is not deleterious to your health because it’s iron. When consumed in reasonably small quantities, rust is only a health concern if you already suffer from hemochromatosis, which is when you have an elevated amount of iron in your system.
Toaster Report writes that the problem arises when rust is left unchecked. Those rusty patches of worn iron can turn into holes in your toaster oven, which both hamper your attempts at cooking and present potentially dangerous situations. However, you can prolong the lifespan of your toaster oven by cleaning out the rust on a regular basis. In their in-depth guide for rust removal, SFGate recommends using a rust cleaner, baking soda, vinegar, a plastic brush, sandpaper, and a lot of elbow grease.