There's a silicon gasket, and they offer a stainless steel plunger upgrade. There is some plastic in the portafilter that coffee will touch (unless you run in bottomless mode).
The bigger problem with most espresso makers (but not the model I linked) is that they use brass for the heating block / boiler and that leaches lead into the water.
This matters less in coffee shops (where they use up the water in the boiler in a few hours or maybe a day), but a lot more at home (where you might only refill the boiler once a week or even once a month).
