PG lasts for about 2 years.
Nicotine solution lasts about 1 year.
VG is 4 years.
PG and VG are roughly the same shelf life if stored properly with PG being slightly longer and both about 2 years.
My info is from Proctor & Gamble who manufacture (USP) both.
As for me it's glass all the way. You only have to open a storage area where you keep your flavors or
eliquids and be knocked over by all the co-mingled smells to know the pet or ldpe plastic bottles which most vendors use are just not air tight.
For those who DIY don't forget to store your flavors in glass, IT MAKES A DIFFERENCE. Wizard Labs sells their flavors in glass vials.
Wizard Labs
As a side note'''I just got off the phone with Ecigxpress and they said all their flavors with the exception of a few flavors from Capella all are shipped direct from the manufacturers in plastic......FlavourArt, TFA and Capella.........maybe they know they are going to be re-bottled immediately and are looking to cut costs as well?? Either way it is still glass for me!