Nah you read it wrong it's 0.03% Carbon. Steel is Fe + C. Stainless just adds various amounts of other elements, but mostly Ni and Cr, and often Mn. In the formula you gave Fe is still the predominant element, it makes up the remaining to reach 100%. 202 has much less Nickel and slightly more Chromium to compensate (and yes, more Mn while 316 has more Mo). Nickel is a potential carcinogen and even without that, Nickel allergy is a real thing and you can develop it over time with exposure. https://www.atsdr.cdc.gov/toxfaqs/tf.asp?id=244&tid=44 In fact 316 and 316L are the worst grades for our application as a heating element. They have a lower TCR precision and they contain more Nickel. We would be better of using 304 or 430.