I just noticed that the metal part of my Philips sterilizer is rusty. anybody else has this issue? I've only used it for 3 months. is it harmful for baby?

i went Phoon Huat aka Redman and bought a pack of Citric Acid powder. 1 tablespoon to 100ml water. Turn on the steriliser let it boil and after it off. Let it stand for 30 mins. pour away the water and wipe inside dry... no smell after that as compared to the vinegar which i had also tried...