Metal beds that are coated with powder coating are much more durable than conventional solvent based paints, but you do need to stay away from certain types of solvents, which can harm the coating. These include such items as nail polish remover and paint thinner. Also stay away from wax or abrasive cleaners, which can also damage the finish.
The website of www.eco-furniture.com suggests caring for your metal bed by dusting frequently with a clean, specially treated dusting cloth that will attract and hold dust particles.