Polyethylene??

[floppy]

Is it safe for a fermentation tank? It's bpa free

[cob]

posted sober reconsidered after a couple stiff ones.

[Ma Flodder]

Polyethylene, and especially HDPE (High-density polyethylene) is indeed safe for fermentation - in fact most buckets sold in brewing shops seem to be made from HDPE.
It is *not* safe with stronger alcohol so never store the result of your distillations in it. It can only withstand high temperatures for a very short time so think twice before emptying a bucket of boiling water or grains in it. An even better material that can withstand high strength alcohol and high temperatures for a longer time is PP, Polypropylene.

https://en.wikipedia.org/wiki/High-density_polyethylene" onclick="window.open(this.href);return false;" rel="nofollow
https://en.wikipedia.org/wiki/Polypropylene" onclick="window.open(this.href);return false;" rel="nofollow

[Danespirit]

You'll find the answer here: http://homedistiller.org/forum/viewforum.php?f=33
Also, HD Google search is an excellent tool.