This topic has been of concern to me as I have spent so much time (and money) researching and testing preservatives. I had and still have so many questions but could not quite get satisfying answers to them about preservatives.
Recently, a new lotion formula that I used grew bacteria and I was not sure whether to blame my ingredients or the preservative that I used.
This post will be answering basic questions about using preservatives in DIY formulations.
USING PRESERVATIVES IN COSMETICS
1. Should I use a preservative?
If you are formulating lotions using water as ingredient, then the answer is YES. If water is introduced to or will eventually be introduced into your product, then there is a big chance that the product will have mold growing in it.
This is because bacteria colonies find watery environments a good place to thrive. So unless the product has a high pH or does not contain any water, it DOES need a preservative.
2. What might we be able to use as preservatives?
There are several kinds of preservatives in the market. They could be broad spectrum or narrow spectrum. According to Microchemlab, they exist in five categories: Parabens, Formaldahyde Releasers, Isothiazolinones, Phenoxyethanol, Organic acids (Read more here).
What you can use as preservative is also dependent on what ingredients that are going into your products. Food ingredients and clay are really hard to preserve and this eventually takes you back to your research work where you have to find the right preservative combo to use.
3. What should one look out for before using a preservative?
What one should do is exhaustive. The best advice is to do some research on what kind to be used in the product.
What one should NOT do is assume that a product does not need any preservative especially when it contains water. Some preservatives do well in oil based products while some are better in the water phase.
4. Is there such a thing as too much preservative in my lotion?
Preservatives are meant to be used at certain percentages therefore yes, there is such a thing as too much of it.
5. How much preservatives should one use?
The quantity to be used is dependent on what kind is used which is why you are advised to do your research in addition to purchasing from trusted sources.
“What you can use as preservative is also dependent on what ingredients that are going into your products. Food ingredients and clay are really hard to preserve and this eventually takes you back to your research work where you have to find the right preservative combo to use.”
6. Is Paraben a good preservative?
Yes it is. Parabens are broad spectrum preservatives that work with a wide pH and temperature range. There are controversies surrounding parabens as a cause of cancer and for this reason, people avoid the preservative altogether even though there is no proven evidence yet to this speculation.
7. My preservative did not work and bacteria grew in it.
The only way to assess if the preservative is working is by a challenge test or preservative efficacy test.
8. Can my fridge act as preservative?
This is not advisable especially as the ingredients in your products may degrade at different temperatures. Relying on storing in the fridge to use within a long period of time is totally unsafe practice and highly unprofessional and because it is assumed that you are a professional, you must not rely on storing your products in the fridge. Even food kept in the fridge has a shelf-life.
9. What if I use Vitamin E as preservative?
As a scientist, I understand that vitamin E is an antioxidant however I went ahead to experiment using it as a preservative in my water-based lotion. It turns out that all that was said about this antioxidant not being a preservative was correct! My lotion started to house bacteria after the second day when it was left at room temperature.
Vitamin E is an antioxidant which means that it slows down the oxidation of oils. When oils are exposed to environmental conditions including temperature change, metal packaging and especially exposure to Oxygen, they tend to be oxidized and gradually become rancid.
10. What if I do not see any bacteria in my lotion when I store in the fridge?
Your eyes can only see so much and your nose can only smell so much. It is possible for bacteria to grow in your lotion right before your eyes and you would not suspect a thing.
Not all bacteria can be seen with the naked eyes, which is why you are told to test your products in a reputable laboratory before selling. A preservative-free lotion stored in a good fridge can only last for a couple of days (2-4 days) because the fridge only slows down the rate at which bacteria move in.
Do you have any questions or contributions? Did I miss something? kindly leave a comment below.