Among Irish Cream liqueurs, particularly lower-shelf than the big names, do any use an all-out unrefrigerated-single-serve-coffee-creamer approach to achieving shelf stability, i.e. tetrasodium pyrophosphate and other preservatives? If so, any clues as to which do and which don't? Can assumptions be drawn based on ABV? Price? Other factors?
Baileys and other Irish Cream manufacturers state that their liqueurs do not need to be refrigerated. As long as they are stored between recommended temperatures of 41ºF/5ºC and 70ºF/21ºC and kept out of direct sunlight, they have a shelf-life of around 2 years.
The alcohol in the product acts as the preservative on its own - so no need to look for anything containing artificial preservatives (in the cases where you can actually find an ingredients label.)
As far as an "unrefrigerated-single-serve-coffee-creamer" version goes - as with almost all types of alcohol, there are plenty of companies that produce miniature versions of Irish Cream, Baileys included:
Considering that the shelf-life is going to be around 2 years whether the bottle is open or not, the miniature versions are manufactured more for consumer convenience than for shelf-life stability.