NDA FO Usage Rates

[Stacy]

I was looking at some fragrance oils from New Directions Aromatics and some of the usage rates are very low.

For instance their Lavender FO (https://www.newdirectionsaromatics.ca/lavender-fragrant-oil-p-2291.html) has the following recommendations on their MSDS:

Cosmetics (0.1 – 0.5%)
Candles (0.1 – 0.5%)
Soaps (0.5 – 1%)

I've made soap with it at 1% and even after a 4 week cure there's still plenty of scent.

I understand each FO is different, and the chemical makeup is what dictates the usage rate, but is there a general rule?

For instance are these low rate FOs more concentrated or are they "harsher"?

I know I'm probably trying to simplify a really complex question, but even general info or a point in the direction where I can pick up useful info on this would be appreciated.

Thanks as always!