the FDA doesn't have an entirely clean track record, and I have no particular need for using disposable PET or PETE water bottles, so I generally try to avoid them, but I don't religiously abstain.

I don't discount the possibility they are for the most part safe, or present negligible harm, but I also don't discount the possibility they are more harmful than governmental agencies present them to be, either because of honest ignorance (not doing sufficient long-term studies on low level PET leaching exposure), and/or via pressure from petroleum companies (the manufacturers of the plastics)

any possibility appears decently probable in this case, so I just choose to avoid as much as I can without sacrificing too much convenience (would still bring disposable water bottles on road trips and buy them in countries with questionable taps)