Okay to use old radiant plumbing for potable?

[KD4UPL]

I've had a Portage and Maine stove installed since 2011. Their instructions say to use Wood Burning Furnace Water Treatment in the water at 1 gallon per 150 gallons of water. The stuff is made by Certified Laboratories. It says "severe irritant, harmful if swallowed".
I recently changed my plumbing and have lots of 3/4" PEX pipe, fittings, and valves left over. They had this solution going thru them for about 6 years. I would like to reuse some of this to plumb my domestic how water plumbing. I don't know if it's a concern that there is some residue of this chemical in it or not. My main concern is a mixing valve, these cost over $100 so I'd like to use this one instead of buy a new one.
Does anyone know anything about this chemical? Does it "hang around" in old pipes and fittings? Would it get flushed out quickly with potable water?
Thanks,

 

[Bad LP]

No freaking way would I use it.

 

[maple1]

Pretty sure I wouldn't either.

 

[Fred61]

ditto!

 

[tom in maine]

Plastic tubing grows bio slime as a layer on the inside of tubing.
It is possibly cleanable, but with what I could not tell you. Legionaires likes to live in tubing that is not being used. Radiant systems are cool all summer.

PEX is cheap enough, it is not worth the risk.