Reaching waaaay back to University days, IIRC Stainless can either be Austenitic (non-magnetic), or Ferritic (see the Fe = iron) and martensitic which are both magnetic. Stainless primarily differs from carbon steel by the large increase of chromium content compared to carbon. Stainless is less of an electrical conductor than copper, although we used Inconel (added copper) on the welded terminal lugs of 5500Kw resistors - yes resistors.
Two examples,
304 stainless is non-magnetic and is used in the food industry frequently with Fe being a fraction of a % or so.
318, a general stainless, with a composition of 3 to 12% Fe, and is magnetic.
So, Tom needs a fridge made from 304 or its' derivatives.
Another fact, stainless can be attacked by bacteria at elevated temps, think of high temperature pipes in a power plant.
All right - more than you ever needed to know, sorry - don't know why this is still stuck in the brain.