How do you make sure the blend you are creating is still skin safe and safe at the rate you are using?
When using plant based FOs from FNWL (fromnaturewithlove.com) Each product has a percentage of usage chart and I normally use the "rinse off" category as recommended per product. Or alternatively I use the amount of scent recommended in the soapcalc.net.
When using EO depends on the EO. Most of my EO are from Edenbotanicals.com and Woolzies 10 grams (plus or minus a bit) per lb of oils in CP soap seems to work well.
FO seem to be entirely proprietary so it is very difficult to know exactly what is in them.
EO are much more easily worked with for me because I know exactly what is in them.
Skin safe. I research the EO and try to use those that are generally well received such as Chamomile, Lavender, Ylang Ylang, Rosemary, Litsea Cupeba, Lemon Verbena, and the more common EO's found in skin products.
Have found the citrus EO soaps to be the most difficult to retain a scent with EO usage. The lye seems to simply "eat" the EO. Today I tried a mix of Lime, Orange, Vanilla, and Vetiver EO and it was pretty nice (but the Vetiver is very pricey).
Hopefully I am not making mistake with my measurements. Haven't sold a thing yet, but have some friends that are testing my first attempts. IF and when I do sell a product I would list the EOs on the label so Buyers could determine allergic issues.
Personally I am severely allergic to latex and it seems to have crossed over into other plastics. So I have difficulties with foods and items wrapped in plastics. That is why I started making my own hair shampoo and conditioner. Have a grand daughter that is allergic to nuts, all dairy, sesame and a few other items. Allergies are a huge concern for me. Skin safety is part and parcel of the same concern.
Thank you for your question. Hoping for your opinion on my measuring methods. Best,