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?

Same as Louis, I used Citric Acid Powder which cost about $3 per pack from Phoon Huat. Remove all the baskets, add water into the metal part, then pour the citric acid powder in, let it boil for 1-2mins and manually switch it off otherwise water will all dry up. Wait for 30-45mims before using a brush to scrub off the dirty things on the metal and clean them off. Must let the sterilizer run without sterilizing bottles at least once. It is recommended to clean at least once per week. Alternatively, you can use fresh lemon too. But personally, I find citric acid powder works better in cleaning the metal part.