Essential oils in natural flavourings can separate, and need shaking constantly before using them as a concentrate and during steeping once mixed and before adding to your tank before vaping. these type of oils are used regularly in "Natural Flavours" and from my limited understanding aren't dangerous to vape as they are not lipid oils.so long as they are not solvent based, but have been distilled or in the case of citrus fruits usually cold pressed.
I have no idea if this is what is being used in this particular concentrate. But if you contact firstname.lastname@example.org he is usually very helpful and will answer any queries or worries you have about their products, from past experiences.
This is another reason I try to buy direct from a manufacturer where possible. As I trust the level of oil in my 10ml of concentrate or whatever size bottle is correct for that proportionate size of bottle. Oil in concentrates tend to sit at the top in my experience and unless shaken before use will stay separated so you can varying amounts of oil in your initial mix because of this which effects the finished flavour and strength of flavour you can end up with in your mix, even though I am using the same amount of that concentrate in different mixes.
Would a vendor rebottling a 100ml or 1 litre bottle of concentrate shake vigorously before decanting into 10ml bottles? Or if I get some of the last bottles of the decant am |I likely to get a higher proportion of oil than an earlier decanted bottle? iyswim.
We have several concentrate manufacturers on here Walt @ Realflavours springs to mind. Maybe Daath could approach him to write a post explaining "Natural Flavours" and essential oils and what is safe to vape and what isn't when it comes to oils. I would certainly find it helpful and maybe others.
P.S. If this was to happen a post on the safety of Palm Based VG would be also useful?