- by Luisa
The ultimate list of natural preservatives for cosmetics.
Two days ago, I received an email from a potential customer who wanted to hire me for an "intimate parts" product.
We scheduled a phone call to further discuss the project. During our phone conversation, I found out that this client wished to add probiotics to the product .
My first comment was:
"There's no way probiotics can survive in presence of the preservative".
This is what that prospective client replied: "DON'T ADD THE PRESERVATIVE, THEN. "
There's a new horrible trend going on. It feeds itself on the (false ) belief that everything that is natural is good and vice versa. As a consequence, some brands started making "preservative free cosmetics".
According to some people, preservatives are not necessary and can be even harmful.
It's true that a high number of skin allergies and reactions are caused by preservatives and fragrances, but...this is not a valid reason to avoid using them.
What you can and should do is to inform yourself about the preservatives that are less likely to cause bad skin reactions.
Want all natural products?
I get that.
But, even natural products should be safe and include a preservative! Just because you don't see any sign of spoilage, it doesn't mean it's not here. We know cosmetics don't have to be sterile. It would be quite ridiculous. At the same time, you don't want an excessive number of bacteria in them and no pathogen ones at all. Sure, not all bacteria, fungi, and mold are dangerous; however, even the innocuous ones could prevent the product from working the way it is supposed to.
As brand owner, you have the legal and moral responsibility of making sure the products you sell are safe. Period.
Misconceptions about natural preservatives
Every now and then someone asks " is glycerin a preservative" ? The question probably arises from the fact that products with a high concentration of glycerin usually don't require a preservative; BUT the glycerin has to be at least 50% which makes the products too sticky.
Furthermore, if you read some DIY blogs, you'll see that some other ingredients are labelled as preservative, yet they're not. To be precise, some might have antimicrobial properties , yet in most cases they're not enough to fully protect a water based product from spoilage.
Let's see what these supposed "natural preservatives" are:
- Vitamin E is not a preservative. It's an antioxidant.
- Essential oils are not ,generally speaking, enough to preserve a product from fungi, bacteria, and mold; however, it's absolutely true that essential oils have anti bacterial properties. The main issue with essential oils is that they tend to have a high affinity for the oil phase of an emulsion, thus limiting their accessibility to the water phase. Furthermore, they might be active against some bacteria , but totally ineffective against other strands. For example, it is well known that Tea Tree oil is not effective against Pseudomonas Aeruginosa. For this reason, if you do attempt to use them as preservative, make sure you use a blend or different oils rather than a single one. Finally, other ingredients might interfere with their action; before you sell products with essential oils as preservative, make sure you perform the preservative challenge test.
"Omnia venenum sunt: nec sine veneno quicquam existit. Dosis sola facit, ut venenum non fit" (Paracelsus)
As the wise Paracelsus figured out many years ago, the dose plays a crucial role as well; to exert their function as preservatives, essential oils should be present as combination and at high doses (sometimes more that 3%). These high doses are extremely irritant for the skin; this is why essential oils cannot be used as preservatives.
Are there cosmetics that don't require a preservative?
Products with no water don't need a preservative; however, if you suppose they'll come in contact with water during use, then a preservative will still be necessary.
For examples, oils mixtures do not require a preservative as there's no chance bacteria are going to grow in them without water. From a stability point of view, though, oils still need something able to preserve their good qualities over time...they need an antioxidant.
Fats are well known to become rancid without a good antioxidant. Vitamin E is a popular and effective antioxidant. This is why it gained the wrong preservative reputation.
To summarize, vitamin E does help to preserve a product, but from a physical stability point of view only. It is not able to kill or prevent bacteria growth.
Other products that don't require a preservative are those with pH values below 4 or above 8 and products with a high content of alcohol (perfumes), salt, or sugar.
Lotions always need a preservative system especially when the water phase is external.
Natural preservatives for cosmetics: the ultimate list.
As stated above, you should always add a preservative no matter if you want to keep your product 100% natural.
The good news is that there are many different all natural preservatives for cosmetics. Don't listen to whoever says natural preservatives don't work very well. I've formulated many lotions with all natural preservatives, and they all passed microbiological tests.
Here's a list that includes natural preservatives that I have tested and worked. The list is not exhaustive, so I invite you to comment with other options you have personally tested.
This is my favorite natural preservative (if something like favorite preservative exists ).
MINASOLVE GREEN B (more info here). Ecocert/Cosmos Approved. INCI: Pentylene glycol (and) Water (and) Sodium benzoate (and) Benzoic acid. Recommended use level : from 1% to 3%. Works best at pH below 6.
Would you like to receive an extract from my latest ebook? Just write your name and email below!
Formulating with natural preservatives like a pro: guidelines and tips.
I don't know how familiar you are with preservatives, but I am pretty sure you know that there's tons of them out there.
How to choose the right one (or the right combination)?
When it comes to cosmetic regulations, always take EU as a reference.
Natural preservatives for cosmetics: conclusions.
In this post we have learned that water based cosmetics (for example hair products, face masks, lotions, makeup etc) do need a preservative to perform the way they're supposed to and to be safe.
We have also learned what are the most popular natural preservatives for cosmetics and how to formulate using them; my final recommendation is to try those that are aligned with your or brand's values and see which one gives you the longest shelf-life.
Finally, to test shelf life and efficacy, you'll need to perform PET test (Preservative Efficacy Test). Since this kind of test can be quite expensive, I would recommend to try using a microbial Test kit before. It consists of a plastic slide coated on one side with terrain for bacterial growth and on the other side with Agar for yeast and mold growth.
Now I want to hear from you! What is your natural preservative of choice when making skincare?