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Simple Facial Mist/Toner (preservative question)
Hi there,
I’m working on a gentle, simple facial mist/toner to add to my skincare line and want to use only two ingredients: alcohol free witch hazel (75%) and lavender floral water (25%).
According to the MSDS for both these products:
The alc-free witch hazel consists of:
-Witch Hazel, concentration: 98 - 99.9%
-Benzoic Acid, conc.: 0.13 - 0.17%The lavender floral water consists of:
-Lavender Floral Water, concentration: Greater than 95%
-Vegetable Glycerin, conc.: 1% to 3%
-PEG-40 (Hydrogenated Castor Oil), conc: 1% to 3%
-Potassium Sorbate, conc.: 0.3% to 1%
-Lactic Acid, conc.: Less than 0.1%
-Dimethicone Defoamer, conc.: Less than 0.1%My question is, should I use Liquid Germall Plus as an additional preservative? And at what percentage? Max 0.5%?
Thanks!
Juli -
10 Replies
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I would add a preservative. Percentage depends on your manufacturing conditions.
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Yes,definitely add a preservative. With any type of botanical extracts I usually use preservative at the upper end of the recommended usage range.
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Thanks!
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Considering: this is a spray bottle; both ingredients are already preserved adequately with a mixture of benzoic acid and sorbate; I would only add a small amount of preservative. The lactic acid in the lavender water is to ensure the pH stays within the effective range of sorbate so check that the pH <= 5.5 in the final product.
Your idea of Germall Plus, I don’t agree with because of “Not for use in products intended to be aerosolized” according to the site. I suggest adding 0.2% sodium benzoate and ensure pH is less than or equal to 5.5 -
Thanks for your input @Belassi. I’m using non-aerosol bottles, but you still think Germall Plus should be avoided in that case? I will look into sodium benzoate. Thanks again!
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a spray bottle produces an aerosol, it is merely a synonym of mist.
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“Aerosol” has two or three definitions. There’s a legal definition, which requires a pressurized spray. Then there’s the chemists definition of aerosol, which means the same as spray/mist, no matter how it’s produced. And there’s the common definition of aerosol, which means anything that comes out of a spray can, but nothing else.
When you look at usage warnings, use the chemists definition.
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So, what is the correct preservative for spayables then?
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Why not just use Potassium Sorbate/Sodium Benzoate? … something like Sharomix 713 … the same preservatives that are used in your component ingredients.
There is no one “correct” preservative for sprayables … simply use the preservative that is correct for the formulation. But, if you’re concerned about salting in the nozzle, I’d stick with liquid preservatives like benzyl alcohol (and) dehydroacetic acid or propanediol/benzyl alcohol/pentylene glycol
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Suggest Geoguard Ultra (Lonza) a mixture of gluconolactone and Na benzoate if your PH is about 5-5.5.It is also a good buffer and Eccocert approved-1% wt/wt should do it for challenge test
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