Concentrate, fragrance formula, total concentrate are all the same; they are the undiluted mixture of Aroma Chemicals and Naturals that go into a Perfume. Juice and final compound are the diluted fragrance for use on skin. Popularity does not matter in the least to IFRA. They are only concerned with safety. Through their research they have established that Iso E Super has the potential to act as a sensitiser and have decided that if it is used below a certain concentration this potential is removed (or profoundly lessened). IFRA regulations do not just cover alcoholic fragrances, but any product that has a fragrance in in that may be applied to skin. Indeed the regulations differ between a fragrance (such as EdP) designed for a woman's skin and an aftershave designed to go on a man's skin; the argument being that the aftershave could be put onto recently shaved, and so abraded skin which would be more sensitive.
In 2002 IFRA said that 10.0% of a fragrance concentrate could be Iso E Super. LAter on IFRA regulations changed to cover the concentration of a fragrance in the final product. So the 2010 regulation applies to that. For example the use of Iso E Super in a female fragrance is restricted to about 1.3% in the final product , and in the case of a female fragrance the concentrated fragrance would be diluted to about 15.0% in alcohol. Other products, such as Hand Cream would use less fragrance (generally about 1.0% perfume) and so more Iso E Super could be used in the concentrated fragrance.
It is complicated. I sometimes wonder if this is not done deliberately.
Hope this makes sense.