I'm brand new and I learned from reading that Kurt has good reasoning behind his posts.
Kurt,
I saw someone ask something I wondered about...maybe you can shed light, pun intended. If nic is stored in a dark freezer in glass, why does the bottle need to be blue or amber?
It doesn't in the dark freezer. But it takes me many weeks to get
through 50 mL of 100 mg VG, so for me the amber glass is most important when that bottle is out and being dispensed from. That said, I think the light thing is overplayed in general. The issue is UV light, not visible light, and glass filters out UV, even colorless glass. Still if amber or blue is available and cheap, why not? Nothing is going to stop room temperature oxidation of nic with O2 dissolved in the PG or VG...that's where virtually all the yellowing comes from, unless the bottle is left open...and even then the O2 absorption with a eurodropper insert is negligible.
The freezer storage thing was something I figured was valid, and after lengthy discussion with DVap, another pro chemist here, I went ahead and did it and posted the results. The main issue for me was if there was any expansion from freezing, as the kinetics and probable reactions were very clear. Neither expand with cold, maybe because neither actually go into a clear phase change to solid (PG not at all, VG gets really viscous).
That said, if that 100 mg VG is filled almost to the rim and then stored, say in the winter time when house temp is ~60 F, the liquid
will expand if the bottle is brought out for dispensing into a warm room in the summer time, when ambient temp may be quite high. I've had a bottle start leaking in the heat of my office. So I have learned to bring the bottle up to room temp on a few paper towels, just in case, if the room is warm, and have gloves at the ready if leaking occurs. I've discussed this with vendors, and they can have the same problem. PG and VG are more prone to leak than build pressure. So I would leave ~2 mL head space in a 50 mL storage bottle when you fill them for storage, just in case. BTW for those bottles, 50 mL is not to the rim, its to the point where the bottle starts to taper in. They will hold several mL more than 50 mL.
