I'm curious what you're basing that number on?
From an article I read two years ago written by an engineer (
chemical), who worked with liquid nic, the report seemed to summarizing his experiences with shelf life under various storage conditions. Wish I could find it again, was very informative and went into great detail including room temperature storage. I believe it was written with us in mind (
vaping), regular people storing liquid nic at home.
He stated that oxygen, heat and light (
UV), all cause nicotine to degrade. Colored, airtight, -full- glass containers help negate the effects of oxygen and light leaving only heat to contend with. He indicated that liquid nic
cryogenically stored would remain perfectly viable for many decades but that as storage temperatures rise (
to that of home freezers), so does the rate of degradation. Stored in a typical -frost free- household refrigerator/freezer
(+5 to +10F), nicotine still degrades albeit at a slower pace, it's just not cold enough and defrost (
frost free), cycling was a concern. He "speculated" the loss to potency after 10 years
could be 10 to 20% when using a typical household "frost free" refrigerator/freezer for storage. I believe a great many people will be storing it this way.
He did indicate the colder the storage temperature the slower the rate of degradation and recommended using a dedicated chest type "deep" freeze that is -not- frost free, they can achieve temperatures well below -20F and don't "warm" the freezer's contents in order to purge frost. I remember that maintaining temperature below -0F was important for longevity.
I'm hoping that liquid nic properly stored and kept below -10F (
manual defrost, -
no- warming cycles), will remain viable and potent
far beyond the 10 year mark. That's how I'm storing the bulk of my liquid nic but just to be safe I've taken potential potency loss into consideration when calculating total storage quantities. Reports from several people who've properly stored nic for 6 years has been very positive so I'm pretty optimistic about the longevity. Personally, 15 years down the road I'm more concerned about taste than potency, as long as the nic tastes "fresh" I won't mind increasing the amount that's required when mixing.