Oil used for flavour in e-liquid safe?

Hey there,
I've been vaping over a year and recently I bought "menthol" flavour e-liq (nic-salt). After walking out of store I read the label and I noticed in ingredients, there's "orange oil". I got kinda confused, I never vaped or had liquid which was using any of the oils for any of the flavouring. I checked my e-liquids that I usually vape, and none of them had any oils whatsoever (it's just artificial or natural flavouring).
Is it safe to vape e-liquid which is using oil for flavouring?…

Oil used for flavour in e-liquid safe?

Original source: https://www.e-cigarette-forum.com/threads/oil-used-for-flavour-in-e-liquid-safe.965915/