Once I made the decision to produce and sell natural products, I knew that I would not use preservatives. A lot of research has gone into developing the recipes that I use. I had to find a way to extend the shelf life without using preservatives. I chose Vitamin E oil.
“A preservative is a natural or synthetic ingredient that is added to products such as foods, pharmaceuticals and personal care products to prevent spoilage, whether from microbial growth or undesirable chemical changes.” www.cosmeticsinfo.com
Among natural preservatives, one that is most often used in water based products is Grapefruit Seed Extract [GSE]. It is believed to be effective for “more than 800 bacterial and viral organisms, etc.” However it’s use is controversial because many kinds of GSE contain synthetic preservatives. http://www.achs.edu
Other natural preservatives are honey and rosemary extract. The product you are making determines which ingredient and the amount you will want to add. http://www.dweckdata.com/Published_papers/Natural_Preservative.pdf
At this time, I am using Vitamin E oil to extend the shelf life of my products. Vitamin E oil is an antioxidant “it is added to a product to protect it against damage and degradation caused by exposure to oxygen.” www.cosmeticsinfo.com
Also, “When Vitamin E oil is added to an oil based product, the shelf life of the product or oil goes from 5-6 months to 1-3 years.” http://www.aromantic.com/vitamins-skin.htm
I am currently using Hair Butter that I made 3 years ago; but never opened. I have been using it for six months and it is still good. However, some Herbal Hair & Scalp Oil that I began using about one year ago is now beginning to smell rancid. Exposure to oxygen and whatever may be on our hands when using a product [bacteria, mold, fungus], will gradually destroy the vitamin E molecules. Eventually the product becomes rancid. At that it is damaging to your skin to continue to use. [see aromantic.com]
Products containing water cause another problem. “As soon as any sort of water base is added to a compound, that compound will develop mold, bacteria, and other nasty organisms in very short order unless a preservative is used. This will happen eventually even if that compound is refrigerated.” http://www.simply-eden.com/blogs/preservatives/5901597-vitamin-e-oil-as-a-preservative.
Because my shampoos are water based, I make them in small batches; add vitamin E oil and salt to help extend the shelf life by a few months. Keeping the shampoo cold and using tea tree essential oil helps as well. Using a non-aerosol airless pump also helps to extend the shelf life. You don’t touch the contents and no air gets in, because the product does not flow back into the bottle.
In some circles there is a debate about whether to use preservatives or not. It is becoming easier to keep products and ingredients long-term without using potentially harmful ingredients.
For more information on this subject see: http://www.naturalcosmeticnews.com/new-ingredients/the-most-popular-natural-preservatives-2/;