Dan, Thanks for your response! I will be reading up on prop 65. I am not concerned specifically with the Silvia, i am concerned with any espresso machine with a copper and or brass boiler. The website I saw that warning on, has that warning on all of their espresso machines, like the Rocket Giotto, for example.
For me personally, I use an 1996 Bezzera BZ40 with a 3.4L boiler (copper with brass endcaps I believe). It is a HX machine, so the brew water gets flushed through quickly, however the water for steaming sits in that huge boiler, probably for a long period of time, because it would never fully get flushed out, unless I manually drain it. I wonder if the longer it sits, the higher the amount of lead that could get leached into the water. I am mostly concerned, because I make my wife 1 latte every day. She currently breastfeeds and we are planning on having another one in a year or so. I would hate for our coffee habit to cause any issues with our kids.
I wonder if there is some kind of test kit i could use to test the amount of lead in the water coming from that machine, to see if the levels are dangerous or not.