Blending Fragrance Oils

[cappykat]

I want to blend two fragrance oils. They are both Black Raspberry Vanilla. One has an IFRA of 3.42% and the other is 25%. I have 1.30oz of the 3.42% and 1.95oz of the 25%. I have 42oz in oils. Here's the math:

42 x .0342 = 1.43oz (I'm using 1.30oz which is 3.1%)

42 x .046 = 1.93oz (this is the 25% IFRA)

Total FO 3.25oz

In Soapcalc.net I used a 1 fragrance ratio which is .0625%. (42 x .0625 = 2.63oz) My calculations using both FO's give me a 7.7% total fragrance percent. Is this allowable?

 

[akseattle]

@cappykat , I have blended some fragrance oils where one had a low IFRA- like 3.42% , and I added an FO with a higher IFRA, like13%, until I had a combined 6%. I only recently started wondering- since I have no idea what in the FO gave the first FO a low IFRA, and I have no idea what is in the second FO, how to know if it is safe.

I was just about to ask this question. How to know if a combination of FO's is safe. So, I look forward to seeing how others figure this out.

 

[AliOop]

since I have no idea what in the FO gave the first FO a low IFRA, and I have no idea what is in the second FO, how to know if it is safe.

That's the concern I'd have, as well. Not sure how to resolve it.

 

[paradisi]

You need to find the chemical that's responsible for the limits. Generally speaking nowdays the EU allergen sheet and/or SDS will show the aromachems that have limits and you can figure it out from there.

You will have to look up those to see what their limits are. Then it's just math.

Example: If frag A has 80% of Limited Thing, 1 oz has 0.8 oz, right? And if Frag B has 5% of that Limited Thing, then an ounce of it will have 0.05 oz. Added, that's 0.85 oz in the two combined ounces. Etc.

But without those info sheets, you can't know if it's going to surpass the IFRA limits to blend them.

 

[Saponificarian]

The EU allergen sheet is your best bet, and I calculate it as @paradisi suggested above, which is how I make my FO/FO and EO/FO blend. Do the calculation before you start so you don't blend, tweak it to get the right blend and then find out you have exceeded the IFRA limit. Ask me how I know each tweak's IFRA must be calculated before making an additional tweak.