Guest guest Posted April 10, 2004 Report Share Posted April 10, 2004 Hi Sue, You really don't need 63% alcohol to ensure preservation. You only need a minimum of 15% ethanol as I stated in my earlier post. The question that was asked of Maurice had to do with the amount of alcohol needed to make a " germ killer " (post copied below). The information I quoted in my earlier post comes from the Cosmetics & Toiletries Ingredient Resource Series, Preservatives for Cosmetics by D.C. Steinberg. In there, it notes: " Non-cosmetic approvals: At concentrations above 60% alcohol is approved as a Category I OTC antiseptic in the U.S. " " Activity: Active against everything but dependent on concentration. As a disinfectant (or antiseptic), levels above 60% will show complete kill in less than 1%. " " Inactivators: When the concentration falls below approximately 15%, alcohol becomes a growth medium. " " Incorporation: Alcohol is used as a solvent in many cosmetic applications. Products with concentrations above 15% alcohol are " self-preserved. " That's why it is important that the alcohol be at least 15% in a formulation, unless another preservative is used. Unless is making an OTC disinfectant, she only needs to make sure she has at least 15% alcohol by volume in her formulation (and the alcohol needs to be 95% ethanol (vol./vol.) with water. If she is using 70% isopropyl alcohol, for example, she'd have to recalculate the amount of 70% isopropyl alcohol needed to have the minimum concentration of 15% alcohol needed for preservation. That's also why I use Isopropyl alcohol in a spray bottle when I'm formulating. It's a great surface disinfectant. Regards, Jen >I want to know what percentage of alcohol you should use in a >recipe for it to be a germ killer.ÿ A local chemist told me 65%, but >he works mostly with food and wasn't sure.ÿ I have seen a few >recipes with aloe gel and alcohol and they don't seem to use >much alcohol at all. You'll need 62% to 95% Ethyl Alcohol. Maurice body spray alcohol percentage Di, A long time ago Maurice suggested using 63% alcohol to ensure preservation. I made a note of this because I make eau de toilettes. You could check with him. Sue in Ontario Quote Link to comment Share on other sites More sharing options...
Guest guest Posted April 10, 2004 Report Share Posted April 10, 2004 There was an error in one sentence; it should read: " Activity: Active against everything but dependent on concentration. As a disinfectant (or antiseptic), levels above 60% will show complete kill in less than 1 minute. " Jen ----- Original Message ----- From: Welch Sent: Saturday, April 10, 2004 6:53 PM The information I quoted in my earlier post comes from the Cosmetics & Toiletries Ingredient Resource Series, Preservatives for Cosmetics by D.C. Steinberg. In there, it notes: " Non-cosmetic approvals: At concentrations above 60% alcohol is approved as a Category I OTC antiseptic in the U.S. " " Activity: Active against everything but dependent on concentration. As a disinfectant (or antiseptic), levels above 60% will show complete kill in less than 1%. " " Inactivators: When the concentration falls below approximately 15%, alcohol becomes a growth medium. " " Incorporation: Alcohol is used as a solvent in many cosmetic applications. Products with concentrations above 15% alcohol are " self-preserved. " Quote Link to comment Share on other sites More sharing options...
Guest guest Posted April 12, 2004 Report Share Posted April 12, 2004 >The alcohol I am using is Perfumer's Alcohol by the Chemistry >Store. I wish I knew more about this but I am very new in this area >and just testing it out before I am happy with the outcome. > " This product consists of 90% SDA 40 Alcohol and 10% DI Water. " >What would the correct ratio's be for this? Any help would be >appreciated! 100 = 90 X = 15 X = (100 X 15)/90 X = 1500/90 X = 16.67% So if you add 16.67% of the Chemistry Store's alcohol to your formula, you will have 15% ethanol. Good luck! Maurice -------------------------------------------------------- Maurice O. Hevey Convergent Cosmetics, Inc. http://www.ConvergentCosmetics.com ------------------------------------------------------- Quote Link to comment Share on other sites More sharing options...
Guest guest Posted April 12, 2004 Report Share Posted April 12, 2004 >100 = 90 >X = 15 >X = (100 X 15)/90 >X = 1500/90 >X = 16.67% >So if you add 16.67% of the Chemistry Store's alcohol to your formula, you will have 15% ethanol. >Good luck! This is assuming that The Chemistry Store did their math and dilution correctly. Maurice -------------------------------------------------------- Maurice O. Hevey Convergent Cosmetics, Inc. http://www.ConvergentCosmetics.com ------------------------------------------------------- Quote Link to comment Share on other sites More sharing options...
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