Natalie - can I just add that my eldest son was poisoned by a steam sterilizer. He kept throwing his milk back (and I couldn't breast feed), and was losing weight rapidly. He was about to be taken into hospital for invasive tests, when, for some unknown reason, I was descaling my kettle, and put the last of it into the sterilizer. Within a few minutes, a sludgy brown residue'd formed, & I instinctively knew it was the cause of the problem. The sterilizer'd looked pristine at all times, but obviously WASN'T. To test out the theory, I went back to the old fashioned method of boiling each bottle in a pan. My son drank from that first bottle & was never sick again (I stayed with that method, long-winded though it was, as I couldn't bear to subject my baby to the bleachy smell of tablets). I was compensated by the makers of the sterilizer! x