I think this depends on what you consider "long term" and also what kind of plastic it is. The WL nic that this thread started with was in PET (#1 recycling code) in a freezer for 2-1/2 years before I put it in glass for the test. I actually had four of those plastic bottles and mixed/vaped the other two. They were fine. But I still wouldn't trust it for decades.
And then there's the other plastic that nic might ship in, HDPE (#2 recycling code). HDPE is roughly 50 times as permeable to oxygen as PET is. I've not done any testing with HDPE, in part because I'm not aware of any clear HDPE, but given its high oxygen permeability, there's no way I'd leave nic in #2 plastic for any length of time.
That was my first order from Nude Nic, and my first order of nic at all since this was my initial foray into the mixing hobby. I wasn't aware what their different versions of nic were or even what they were TBH, but likely you ordered their best product with inert gas that displaced oxygen and I order the cheaper product. I know why inert gas is important now, but had no idea then. Even if I had known about inert gas at that time, my conversation with a NN support person on the phone told me it would be best to transfer to glass so I guess the displacement gas would have been a waste for me. Being that I had never mixed in my life, and had no idea whether I would be any good at it or even enjoy it I purchased the cheaper nic and was told the nic itself was the same product. I couldn't tell you if they had an option for their Armor product available in glass at that time, so no idea. I did follow their instructions to use amber boston rounds for transfer to glass since they told me long term storage in their plastic bottles was not advised.
I kind of went wild with my jump into mixing buying over $600 in Nic, flavors, syringes, gloves, face mask, beakers, graduated cylinders, etc. Hey, don't judge me... I take my hobbies seriously! But I did try to research as best as I could given the amount of information that was available in late 2013. That was a heady time for vaping with groundbreaking products coming out on a weekly basis. And I thought the 2 Provari's I purchased within a month of starting vaping would be the only devices I would ever need. The vape shop I bought them from told me that was true. Hah! BTW, the face mask still looks like new and is in pristine condition, probably since I've never used it or taken it out of it's packaging.
For the salt nic from Nic River, this is the first nic product I have freezer stored in the original container. I read on their website that I could refrigerate or freeze it, so yeah. Because I value your opinion, I called Nic River yesterday to verify if their website was correct and the synthetic containers were OK to freeze long term and they said yes and they recommend that it's best not to unseal until I needed to use it. Not sure if they top fill with an inert gas, forgot to ask.
I guess if I trust a vendor with purchasing their nicotine, I tend to also trust their advice on proper storage. But that's not to say I might not regret that decision later, but for now I'll take the easy way and hope their advice was correct. But there is a distinct difference in the synthetic plastic type material I received from Nic River when comparing it to the 2013 Nude Nic material. Does it matter? I guess time will tell.
