Glycerin as a Preservative
“It is also used in the production of watercolor paints, printing inks, and cosmetics.”
http://www.wisegeek.com/what-are-the-different-uses-of-liquid-glycerin.htm
“extracts made from Vegetable Glycerine typically have a shelf life of 14-24 months whereas alcohol extracts can have an extended shelf life of 4-6 years.”
“You can make a simple, herbal glycerite by simmering herbs in a mixture of 60% glycerine and 40% purified water for two to three hours. We have generally used about 1/4 cup of cut and sifted, dried herbs per 1 cup of glycerine/water solution. When you strain this solution, bottle it and store it in a cool, dark place. It retains its effectiveness for two to three years.”
http://www.morethanalive.com/Vegetable-Glycerin
“It seems that you can use glycerin as a preservative when you use 50% glycerin or more in a product.”
” foot lotion recipe with 25% glycerin, and it feels great on my feet…but it feels awful on other parts of my body… too sticky.”
http://swiftcraftymonkey.blogspot.com/2012/06/question-can-glycerin-act-as.html
“a water soluble solvent (glycerin) as an alternative delivery mechanism to alcohol.
To be effective as a preservative, you need to have AT LEAST a 50% glycerin content in your formula, and it is best if it is about 60-70%. ”
http://chemistscorner.com/cosmeticsciencetalk/discussion/65/glycerine-as-a-preservative/p1
”
Grapefruit Seed Extract
Grapefruit Seed Extract (GSE) is a citrus seed based anti-microbial used as a preservative in skin care products. GSE is made with the extracts of citrus seeds and pulp. It is blended with vegetable glycerin to make it non-irritating to the skin and mucous membranes when used in formulations. GSE is even safe enough to use as a disinfectant for drinking water when necessary.
Our Grapefruit Seed Extract is professional strength. It is 60% GSE in 40% vegetable glycerin. It is not the usual 33% found elsewhere. Please be sure to take that into consideration when using a recipe that simply calls for “GSE”. GSE has a shelf life of 7-9 years. It is said to be anti-microbial, anti-septic, anti-bacterial, astringent and does also have some antioxidant activity.
Use GSE at .5 to 1% to preserve most formulations, or use at 2% to create anti-bacterial creams, salves, rinses and soaps. Please note that adding 2% GSE to your products does not mean that you can market or label the product as an “anti-bacterial” product.
Wear gloves while handling Grapefruit Seed Extract. GSE can be irritating to the skin in its undiluted form.
INCI Nomenclature: Grapefruit (Citrus Grandis) Extract (and) Glycerin”
http://www.fromnaturewithlove.com/library/preservatives.asp
