Can't help but think all this talk about using plastic water bottles the last few days was stirred up by me, as I mentioned I've done it in the past.
I said its not my usual carry but I've done it. Disagree if you want. Think its inappropriate if you want. All you who think as such are right, but I don't live in a world of rainbows and unicorns. I live in realityville. It's expedient, it's UL. It works. No one I hike with brings 16.9oz water bottles so its a unique item in the group. Plus it's well marked. And 9 times outta 10 the leftover gets poured back into the original can or my MSR bottle.
My kids, if they ever got into my gear cabinet, which they don't, would never confuse it for an old half full water bottle and drink from it. And they've been raised well enough (or spoiled enough, hmmm) to not drink out of a water bottle that they don't know who drank from it or how long it sat out. I have Denatured alcohol in a MSR bottle that is not otherwise labeled as fuel, and I drink from other stainless bottles around the house. My kids have never thought one was the other.