I searched and read a million different opinions but could not find a difinitive answer.
I would thinkit is safe as no matter where it is on our home pluminb, water still goes back to nature, and it would not be appropriate or acceptable for us to put something into the water that would be unsafe.
I am only using a small section for the overflow area to create a diy stockman standpipe. ABS is the only fittings I could find that would allow me to create that inverted cap / cone detail.
Thanks
Bill