I realized after I posted my final facial moisturizer ingredients list that I forgot to list the preservative! I have edited the post and added it, but I wanted to comment about what it is and what I like about it.
The preservative I chose is citric acid (and) silver citrate, which is an all-natural product. When considering the types of preservatives available, this one has caught my attention, not only because it is natural, but also because it requires so little (0.1%) to be effective. I will have the final formula challenge tested in a lab to be sure that my formula is safe and bacteria-free before selling it.
When considering the types of preservatives available, parabens have become controversial because of a supposed link to cancer. This link has never been verified, but most people would rather err on the side of caution.
Other preservatives are what is known as formaldehyde donors. That is, as they interact with the product they are supposed to preserve, they can produce small amounts of formaldehyde. Also undesirable.
I experimented with a product called Geogard Ultra, INCI name: Gluconolactone (and) Sodium Benzoate which sounds more natural than some others, but isn’t really natural. It’s not a formaldehyde donor, so it has that going for it. However, it is a white powder which must be dissolved in water before use (it really didn’t want to dissolve), it requires a large percentage to be effective – especially when you consider that powders weigh much less than liquids, and it seemed to leave tiny air bubbles in my formulas. Bottom line: I didn’t like it!
If you would like to check the preservatives that are in your cosmetics, go to the Skin Deep database.