A rusty grill is not safe to use, especially if the rust is loose because it can stick to food. If the grate only has a low amount of rust that’s thin and easy to scrape off, you can try using a special rust removal spray, which you can apply after heating the grill up. This will make it easier to scrub the rust off using a steel bristle brush. Consuming rust from just one meal is not exactly harmful, but continued exposure can be problematic to the intestinal tract.