Preservatives, ANTIOXIDANTS, FRAGRANCE oils, and Essential Oils

This is part five out of my eight-part series on DIY Cosmetics For Beginners. In this post we are going to be talking about preservatives, antioxidants, fragrance oils, and essential oils. This is going to be a long post. So, I recommend grabbing a notebook to write some of this down.

Preservatives:
Preservatives have a bad reputation for no reason. They are essential for any water-based products or products that will be introduced to water. They are crucial because even in the tiniest amounts of water, bacteria, mold, and yeast can grow. Gross! They also love the pH environment that we are formulating at 5.5. The even more concerning part is that all that stuff can grow within days, without the appearance or the smell being altered. Kind of scary, right? So, there is no way (unless you tested it in a lab) to see if your products have expired. 
Learn about stability testing in this video:
Institute of Personal care Science: Cosmetic Expiry date - Shelf Life - Stability Testing
After all this concerning news. What do we do? Well, this is when preservatives come in. These chemicals are blends to prevent or decrease bacteria, mold, fungus, and yeasts from contaminating the product. Preservatives can be either a powder or a liquid. It usually contains more than one ingredient. The reason is that they need to be broad-spectrum coverage, which means that they combat all the types of contaminants that could grow or be introduced. Depending on the preservative, it can be used as low as 0.5% or as high as 3%. It is imperative that you check the supplier that you purchase from and know all the information. Information such as the usage range, the types of products it can be used in, the pH range it can be used in, the temperature it is safe to be added in, and you should always save the SDS sheet. Note that more natural or naturally-derived preservatives are used at higher percentages and can be more irritating than their synthetic counterparts. If you are using Ingredients that are at high risk, then I would recommend getting your product challenge tested if you are a brand. Ingredients that are high risk include natural gums, hydrosols, proteins, clays, and any botanical. If you are a home crafter, I would use preservatives with more data.  
Let's look at preservatives themselves. There are also several types of preservatives.
Here is a list of the five most common types of preservative in cosmetics:

• Parabens
• Examples: Methyl, Ethyl, Propyl, Isopropyl, Buty, Isobutyl Parabens
• Formaldehyde Releasers
• Examples: Diazolidinyl Urea, Imidazolidinyl Urea, and DMDM Hydantoin.
• Isothiazonlinones
• Phenoxyethanol
• Organic (Carbon Containing) Acids
• Include potassium sorbate, Benzoic Acid, and more

The first two types have gotten an evil reputation in the media. Lots of products have paraben-free labels to meet the consumer's perception. Even though the "scientific study" has discredited. Here is a link to a recent study in 2020 that shows in regulatory limits that parabens are safe (Link) Most consumers and natural enthusiasts still believe this. With that, many people are looking for preservative-free products or natural preservatives. Companies and formulators have options, but it leads to other problems. What preservatives you chose are based on what you feel comfortable with. However, you need to consider some other factors and some other factors.
Factors for choosing a preservative:

• the pH of the final products
  • Can the product be alkalized or acidified to fit the preservative? Or in other words, pH adjusted.
  • Does my product fit the pH range that the preservative calls for?
• What is the product's base?
  • Is it water-based, oil-based, or is it silicone based?
• What is the required temperature for the product to be melted?
  • Can it go into the heated phase, or does it have to go in the cool-down phase?
• Is any of the ingredient going to "deactivate the preservative."
• Is it cost-effective?
• Is it compatible with X ingredient?
  • Protein, electrolytes, etc...

With all this in mind, you can choose the right preservative. I also want to add that making the pH high or low does prevent all the nasty stuff from forming but, the higher or lower we go, the more of a hazard it becomes. It also is controversial if acid-based products or liquid soaps need preserving.
Here is a list of common preservatives *I have used it*

• *Germaben II* 
  • for hard to preserve cosmetics
  • contains parabens (Note: I have overly sensitive skin, and my skin has been excellent using it)
  • Lots of incompatibilities
    
• Use with water-based products
  • Use at 1%
• Very cost-effective and easy to work with
  • Note lots of contradicting information on this product. I recommend doing your research
• Phenonip 
  • Contains Parabens and Formaldehyde Releasers
• Best for oil-based products that are going to be in contact with water
  • Note lots of contradicting information on this product. I recommend doing your research.
• Liquid Germall Plus 
  • Standard
  • Used at 0.5%
  • Add in the cool-down phase
• Optiphen Plus 
  • Natural Preservative
  • No pH restriction
  • Recommended usage level is 0.5-1.5%
• Stir in below temperatures of 176F (80C)
  • Note lots of contradicting information on this product on Amazon. I recommend doing your research.
• If you want "preservative-free" claiming preservatives MakingCosmetics has the best selection.

This is a list of broad-spectrum preservatives. I recommend looking at suppliers' websites for more information on the chemicals.
Work Cited:

• https://ec.europa.eu/docsroom/documents/15281/attachments/1/translations/en/renditions/native
• https://microchemlab.com/information/five-most-common-types-preservatives-used-cosmetics
• https://microchemlab.com/information/natural-vs-synthetic-preservatives
• https://microchemlab.com/information/introduction-preservatives-and-challenge-testing
• Make Your Own Cosmetics! Volume 2 Recipies for Lotions & Butters by Karin Bombeli & Thomas Bombeli, M.D. pages 19-20

Additional Resources:

• The Eco Well: A Guide to Cosmetics Product Preservatives
• Preservatives in Cosmetics by The Institute of Personal Care Science

Antioxidants:
There is a misconception that antioxidants preserve products, but they do not. What antioxidants do is they help oils from becoming rancid. Most oils, whether they are organic, natural, or synthetically produced in a lab, will oxidize. Oxidation is a reaction between the oil and oxygen. To prevent this, we add antioxidants. Some examples are:

• Vitamin E oil
• Also known as tocopherol
• When buying it, make sure it is for prevents the oxidation of oils. I would also avoid any vitamin E oil blends. I am mainly referring to the ones you can get at health food stores. That has a lot of vitamin E but is diluted by oil. To get any efficacy, you would need to calculate the percentage to be effective. I do understand that it is expensive but keep in mind that for the most part, you will be using it at 0.5%
  • Dl-alpha tocopherol is for the prevention of the oxidation of oils 
• Dl-alpha tocopheryl acetate is an active for the skin
  • I have made this mistake, and I have both form MakingCosmetics
• Rosemary Extract
• If you do choose to use this, you need to make sure that you get a high-quality one. Do not get this confused with Rosemary essential oil. 
• Grapefruit Seed Extract
• If you do choose to use this, you need to make sure that you get a high-quality one. Do not get this confused with Grapeseed Oil
• Sodium Lactate
  • Is water-soluble
  • Can adjust pH
  • Humectant
  • Is found in our skin
  • Not suitable for anhydrous products
• Citric Acid
  • Is also water-soluble
  • Lowers pH
  • Not ideal for anhydrous products

When we are making cosmetics, we will be using Dl-alpha tocopherol. I will form know to call it Vitamin E. Keep in mind that lots of websites call it a preservative but, it is not.
Additional Sources:
Institute of Personal Care Science: Formulating with Vitamin E
Fragrance Oils and Essential Oils:
Fragrance oils are another controversial ingredient, unfortunately. The reason is that they are produced in a lab. (eye roll) Many people are sensitive to them, which I am not denying. People feel essential oils are ok because they are natural so that they are perfectly fine as a fragrance. But the truth is that you could have the same reaction to essential oils as you do a fragrance oil.
Another thing is that people do not understand that essential oil constituent are used in the fragrance industry. I have no problem using fragrance oils. It adds an even bigger range of fragrance to my products. Again, it is what you feel comfortable with.
General Advice for Essential Oils and fragrance oils:

• Always dilute your essential oils/fragrance oils
• They are not going to cure every ailment that you have
• Do your research for benefits (Sorry not Sorry Pinterest)
• I recommend not to use essential oil during pregnancy
  • Or with young children
• Be careful with citrus essential oils as they are photosensitizing at specific amounts
• Add them to the cool-down phase
• Usually lasts one to two year
• They are incredibly potent!

My last point about this topic is also another misconception that essential oils are preservatives. Where this comes, from is some essential oils have antibacterial properties, which they do and can be used as a co-preservative. They should never be used as a broad-spectrum preservative.
Understand that there is so much more to these topics that I can't add it all into one blog post! 
I know that this is long, but there are lots to cover in it. The next three parts of my series are the best! They are going to be about formulating Oil-based, water-based, and powder based-cosmetics. They will also include formulations! Get excited!​

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