EO Usage Rate

I'm in the process of making a batch of isg's version of pear's soap and I've heard that the resin/rosin scent won't come through in the final product so I thought I was going to scent it to kind of sort of mimic the scent of the resin. I have narrowed it down to a few EOs that I'm choosing from though I haven't quite decided yet.

The problem is that I can't find a usage rate for any of them, I've heard 0,5% for cassia bark but that you could use more of the leaf oil, but how much is that? Nothing on the other EOs and I've looked on all places I can think of.

The EOs I'm looking for usage rates for is:
Cinnamomum cassia leaf oil (cassia)
Cinnamomum camphora bark oil (Ho wood)
Cinnamomum camphora linalooliferum leaf oil (Ho leaf)
Curcuma longa(turmeric)
Canarium luzonicum gum oil (elemi)

I know I'm asking for a lot. I didn't think it would be this hard to find the usage rates, maybe I'm just missing an obvious place to look at?

This doesn't list them all, but might help.

http://www.modernsoapmaking.com/essential-oil-usage-rates-ifra-guidelines/

Wholesale Supplies Plus lists IFRA usage rates for the EOs that they carry. I would suggest contacting the supplier where you buy your less commonly used EOs for information.

Just consulted my Essential Oil Safety tome by Tisserand/Young.

Cassia: Both IFRA and Tisserand/Young recommend .05% for maximum dermal use.

Ho wood: My Tisserand/Young book doesn't have a listing for Ho Wood, but it does lists 3 different Ho leaf EOs:

1) Ho leaf (camphor CT), Cinnamomum camphora L. It's also known as Hon-sho (true camphor tree). Its majority constituent is camphor (between 42% and 84.1%). Recommended maximum dermal use for this particular Ho leaf- The EU says- .03%; IFRA says- .06%; and Tisserand & Young say- .8%

2) Ho leaf (cineole CT), Cinnamomum camphora L, Chinese synonym is 'Yu-sho' (camphor oil tree) and the Madagascan synonym is 'Ravintsara'. Its majority constituent is 1,8 cineole (50%). Interestingly, in Tisserand & Young's book, camphor is not even listed as being a constituent of this one. Recommended max dermal rate for the Chinese cineole CT: EU- says .2%; IFRA- says .4%; and Tisserand/Young- say 11% . For The Madagascan cineole CT Ho Leaf there are no restrictions from either the EU, IFRA or Tisserand/Young.

3) Ho Leaf (linalool CT). Cinnamomum camphora Sieb. var. glavescens Hayata. Synonyms: Ho-sho (fragrant camphor tree) shiu, shiu-sho (bad smelling camphor tree). Majority constituent is linalool @ 66.7%- 90.6%. Recommended max usage rate: EU says .05%; IFRA says .1%; Tisserand/Young say no limit.

Curcuma longa(turmeric): Under Tisserand/Young's safety summary it states that there are no known hazards or contraindications, and no information to be found on adverse skin reactions. Consequently, no usage rates are given.

Canarium luzonicum gum oil (elemi) Recommended max dermal use: EU says- .07%; IFRA says- .13%; Tisserand/Young say no limit.


As you have probably noticed, Tisserand/Young have a bit of disagreement with IFRA and the EU over safe usage rates of certain EOs Happily though, they do satisfactorily explain in their book in detail why they disagree. For what it's worth, based on their detailed explanations, I personally would have no qualms about following their usage rates.


IrishLass

http://www.eocalc.com/

I find this site very useful with calculating EO usage. At the top is the "Calculate Your Usage Rate" tab, where you can put in which EO(s) you want to use and batch size (oil weight), and the recommended safe usage comes back. She doesn't list all of the EOs you are asking about (i.e. ho leaf, turmeric), but it might be useful as a starting point.

I know this is an old thread; but I am curious as to where you (IrishLass) found EU usage rate recommendations for specific essential oils in Essential Oil Safety? The EU gives no such guidelines, merely mandates that usage rates over 0,01 % (soap) be declared on the label. Nor can I find any such recommendations in the book itself.