What I do know is that if the smell only lasts for several seconds then it is classified as an olfactory halucination but mine like yours happen for hours at a time, almost daily and like you I cannot establish any patttern to it
Am J Clin Pathol 160(1):S19
Belk should have called the chew flakes, flavoured with licorice, dried peaches, etc., plug tobacco, as different from selected leafage, twisted into rolls for pocket biting, called quids. Shortly quid tobacco was a plain leaf, rolled for pockets, and bore the price of the treated pressed cakes
The carton is the wholesale unit that retailers purchase from distributors & that bulk buyers use for cost savings
One more small indirect positive for cigarette companies is that for chewing tobacco products, abatement has been reduced from 60% to 55% making them slightly expensive