I have a Saeco Aroma which according to its specs is all stainless steel. Looks like that one is ok.
For example there is a hospital in Australia (http://www.abc.net.au/news/2017-06-30/lead-levels-in-perth-c...) that has been massively delayed due to lead mysteriously appearing where there should be none and asbestos also appearing where there should be none. From what I know, the sources have turned out to be manufacturers in China either knowingly misrepresenting their products or using contaminated materials in their own manufacturing.
Unfortunately testing is the only way to be sure.
Edit: nope, you're right. SS boiler apparently