Are 300 series and 18-8 stainless steel safe to use for post processing?

From what I understand, most if not all extraction equipment is made from 304 or 316 due to their chemical and corrosion resistance.

I’ve seen a handful of people using hotel steam pans as an alternative to glassware for post processing, which are made from either 300 series or 18/8.

Are 18-8, 300 series and 304 all the same? I’m finding some conflicting info on the interwebs

This article claims that 18-8 and 304 are chemically the same

Where this article makes it seem like they are different

Are these grades of stainless safe to use for BHO post processing? Is there any chance of contamination/leaching?


When you say “safe” here - what are you really asking?

Even with 304 and 316 there is a possibility of contamination/leaching - if things were not cleaned properly, depending on the pH of your BHO/terpenes present, and if the pan has any etching, etc. (aka stuff rubs off, yes it happens. or your stuff is caustic and nibbles away at the pan)

18-8 and 304 are the same in composition. However - sometimes 304 will have other characteristics which might be important to you (like cold and heat resistance).

When I make the switch from glass to steel - I usually go with 316L for corrosion resistance generally. But 304 is often food grade - but again, cleaning, etching, caustics, etc. can change that.

I think what you are asking here is - can you use 304 pans instead of glass. I haven’t had any safety/compliance issues from doing this - most of the time. Occasionally, I’ll get hits for Chromium / Nickel (they test for those in some states) - but in every case I’ve been able to point that back to inappropriate cleaning (in one case someone using the pan to clean unrelated non-food parts x.X and in another case someone receiving a pan and then not cleaning it at all).

Many spools and other equipment parts are made out of the same stuff - similar issues can happen there.

Will they happen to you? Probably not. :slight_smile: I still prefer glass because I can see through it. yes it breaks sometimes. Yes its heavy. And often its more expensive. But darn it all - I like looking through it. :slight_smile: