Natural Preservatives in Cosmetic Formulations

Natural Cosmetic Formulator Joan Morais

Natural Preservatives

I have been using natural preservatives effectively in my cosmetic formulations for over 10 years. Here are some common and important questions and points that every cosmetic formulator and product maker should consider with natural preservatives.

When I refer to cosmetics, I am referring to body, hair and skin care products.

Preservatives in cosmetics are a topic with many differing and controversial opinions. The one common belief in selling products is that they must be properly preserved and safe to use.

Regarding the preservatives presently used in cosmetics, you will find opinions and research that differ and even contradict each other. For example, using alcohol as a preservative, you will find research on why it is good for the skin and research on why it shouldn’t be used in body, hair and skin care products. It is the same with how we eat. Some research says drinking a little alcohol is good for you and other research says it is not good for you.

Preservatives can receive negative publicity by popular opinion and the wide-spread of popular opinion on the internet influences the consumer. Once popular opinion believes the preservative in cosmetics is harmful, there is no point to use it. A cosmetic formulator must move on to find a more effective preservative. More natural preservatives are slowly becoming available on the market. It takes time and research. 

I am introducing a new effective natural preservative in my Pro Natural Hair and Pro Natural Skin Care Courses.

Here are 5 common questions I receive:

1. What Cosmetic Formulations need Preservatives?

Any body, hair or skin care product containing water needs to have an effective preservative. A preservative system to prevent bacteria, yeast and mold (microbes) from growing. Selling your product is very different than making a product for your own use. If you make and use your product, you control the product you made for personal use. You keep the lid on it, store it in a cool environment and make sure it doesn’t get too hot or too cold and use it up quickly. You lose total control of the product when it is sold to consumers. As soon as your product is shipped, the control is no longer in your hands. The product will be transported on airplanes with high altitude pressure, shipped in very hot trucks or go through freezing temperatures. All of these factors can destabilize your product affecting the efficacy of the preservative in your product.

Water-based products must be effectively preserved. Adding a very small amount of water, even water in alcohol (if alcohol is used in a small amount) needs to be effectively preserved. By adding a little oil to water or water to oil,  the oil acts as a nutrient and will feed and encourage microbial growth

An effective preservative creates an environment that is hostile to the microbes and inhibits microbial growth or attacks the microbes and kills them.

Anhydrous (oil-based) products such as body scrubs used in the shower or bath may need a preservative depending on use instructions. The consumer usually stores body scrubs in the shower or bath. The body scrub is easily exposed to water and moisture. If water is introduced into the body scrub inside the container (bacteria and mold) then you should consider a preservative. Consumers will leave the lids off body scrubs, place their wet dripping hands in the container and introduce water. There are oil-based preservatives that are effective but may not be effective against water that has been introduced into the product. This is why many scrubs also contain a water-based preservative.

Creative packaging and thinking out the box may remedy the issue of preservatives in a body scrub. The consumer needs to be educated. The label can state under the directions to never take the body scrub into the shower or bath or place wet hands into the scrub, instead  scoop out one use into a smaller container, cap the scrub and take the one use scrub into the shower.
Airless containers, aseptic one time use packaging. This packaging can use less preservatives but a formulator must know the formulation is clean and microbial testing performed before adding it to the airless container or aseptic packaging. The airless bottle must not be able to be screwed off by the consumer and the product exposed to the air.

2. How to Choose a Natural Preservative?

Choosing a natural preservative depends on the formulation, the type of formulation and how this formulation  is used, the container it will be in, the desired shelf life of the product and the ingredients used in the formulation.

Water-soluble ingredients, Oil-soluble (anhydrous) pH is very important. The preservative efficacy is dependent on the pH. The supplier for the preservative will state the pH range for the preservative. Also, cosmetics are generally in the pH range of 4-6. Bacteria and mold thrive within this pH range for cosmetics.

Stability of the formulation is crucial. The formulation (product)  not going to break down and must be able to stay stable when exposed to cold, heat and light (shipping across states and countries, freezing temperatures and very hot temperatures, airplanes, ships and trucks.

Broad Spectrum Preservative that addresses both gram positive bacteria and gram negative bacteria, typically you need several preservatives to address gram positive and gram negative bacteria, yeast and mold. Each preservative excels in one area and may not be strong in another area. The industry standard for preservation for natural products is 2 years.

Research the Preservative by doing as much research as you can from different independent reputable sources. Be mindful of where the information is coming from. There is a lot of misinformation on the internet and sometimes from the suppliers for the preservative.
Find published research on the skin sensitivities, the processing of the preservative and the impact on the environment and where it is sourced. Also, what agencies approve of it. Check these agencies ingredient lists for the preservative and if they approve or don’t approve of it.

  • Natural Products Association 
  • Whole Foods
  • USDA organic
  • EcoCert
  • Cosmos
  • Soil Association

3. What is a Preservative System?

A preservative system included everything, like building a house, you need a strong foundation, safe and effective electrical wiring, plumbing, etc. Everything matters in your formulation. Here are some tips for building an effective preservative system:

  • Formulation what is the type and use. Will it be kept in cars like a hand cream?
  • Ingredients (Raw Materials) are crucial for a successful formulation. Use deionized or distilled water and make sure to use fresh distilled water every time, not a bottle you opened a month ago, Make sure your raw materials are clean before adding them into formulation. Hydrosols, aloe vera gel, aloe vera juice and extracts may be contaminated before they are added to the formulation. For example most hydrosols are not preserved and can be contaminated. Adding a preservative will not stop the microbial growth once contaminated. Try to obtain a Certificate of Analysis for your raw materials and look at the microbial count on it. You may need to do microbial testing yourself on that ingredient before introducing it into your formulation. 
  • Antimicrobial ingredients are exceptional ingredients to include in your formula. Essential oils have antimicrobial and antifungal properties and will assist with boosting the preservative system.
  • Chelating agent helps to bind metal ions and greatly assist with boosting the preservative. Phytic acid is a natural chelating agent. 
  • Antioxidants like Rosemary Antioxidant and Vitamin E oil do not preserve but offer antioxidant assistance with plant oils so they have a longer shelf life and don’t go rancid. 
  • Water Activity refers to the amount of water in your formulation. Lotions and Moisturizers have 70%-80% water. If some of this water is bound, there will be less unbound water for microbes. Some ingredients assist to bind the water which doubles to boost the efficacy of the preservative. A natural ingredient for this is propanediol.
  • GMP: Good Manufacturing Practices must be adhered to and used every time in production. Setting up a GMP system creates a strong foundation for a successful business and products. Sanitation of your equipment and area is crucial and be mindful of cross contamination. Learn and know about GMP. I cover in detail on GMP in the Pro Natural Hair and Skin Courses.
  • Container/Packaging; Aseptic packaging, impermeable packaging (airless containers) can be part of the preservative system, but do consider consumer use and consumer contamination once they have the product and the consumer placing their dirty fingers into the product or adding more water or other ingredients to a product.

 4. How to Know if the Cosmetic Formulation is Effectively Preserved?

The only way to know if your formulation is effectively preserved is by testing it. You can not see bacteria by the naked eye. If you have sanitized water and contaminated water you won’t know which one is contaminated. This is why we are told not to drink water from bodies of water unless you test it. You can get very sick from bacteria in the water and yet the water can look crystal clear.

5. What is Pre-market Testing?

The FDA assumes the product you are selling is not adulterated and free from contamination and you do the necessary pre-market testing. Microbial efficacy testing is crucial and important and brings peace of mind to the cosmetic formulator and maker when a formulation is tested in a scientific lab. 

Microbial Efficacy Testing
Here are some of the tests. I’ve already written a post on this and you can learn more about it here.

Challenge Testing
Read the post on challenge testing here.

One Month Challenge Testing is now the industry standard.

Two month Challenge Testing used to be standard.

Batch Testing
Plate Counts: Aerobic plate count (APC) Fungal/yeast count (F/YC) 

DIY testing with slides

You perform the test but these should not be relied upon. Scientific lab testing should still be performed.

This information is provided to empower you and not to scare you. Knowledge is power. It is better and will save you money and time to come from a preventative approach. There is so much more information and too much to include here. I cover all of this information in detail in the Pro Courses. I also update these courses with the latest information on natural preservatives in cosmetic formulations. 

I cover the 5 questions in this video: