2 types of vaseline
white and yellow
white has been bleached partly to preserve it and stop it going stale, but some say the chemicals in it make it unsuitable for nostrils
yellow eventually goes "off", smelling and appearing different, and so has a use by date which pharmacists usually ignore
best to often get a small amount of yellow from a pharmacy, asking for a short expiry date
when stale, it smells and looks different.
Ive used it for my dry eyes for many years
I assume the air isnt humidified due to water being heavy ??