Alright, so this is a totally different question and though it feels like it comes out of the left-field, it does pertain to this product. After all, steel can rust and many of the models on the market use the metal. Rust is only going to happen when iron and oxygen react in the presence of moisture or water in the air. This does not mean that steel is impervious to rust indoors, though. If you have humidity issues in your home then rusting can be an issue. It is not as big of an issue with indoor equipment, but understand that it can still happen.