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Updates on DHA/Benzyl alcohol?
I know that this has been discussed before, but I wonder whether someone has developed experience in a range of formulations with DEHYDROACETIC ACID and BENZYL ALCOHOL preservatives. I see more and more brands every day abandoning phenoxyethanol in favor of this preservative.
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6 Replies
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I tried dehydroacetic acid and won’t use it again. It is far too reactive and ruined several formulations. Just to take one example, it reacts with dipotassium glycyrrhizate to form an insoluble precipitate.
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I don’t know about the precipitation, but I can say it tends to turn yellow rather quickly. So if it’s a white cream is what you are after. That might be difficult.
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Agree much too reactive and yellows rapidly.
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Is the yellowing due to oxidation?
I’ve tried DHA in a blend with benzyl alcohol also (Geogard 221) and I particularly disliked the smell. Awful!
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Can be either oxidation or reduction:Uv light induced or by polar solvents like water slowly in storage.Hard to stabilize.
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I have used the Geogard 221 preservative in a couple of o/w emulsion products and only found a slight discolouration over the shelf life of our products (2 years). Just be sure to keep your pH below 6.
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