Essential Oils Blog

Preservatives…When Are They Necessary

 

A preservative is an anti-microbial solution that helps to prevent mold, yeast, and both gram- positive and gram-negative bacteria from growing in your products, without them your product can essentially be a science experiment in the making. Many people feel that placing a preservative in your product no longer makes it natural, and is adding unnecessary chemicals. While it is true that there are some chemicals that we want to stay away from, let’s remember that even essential oils are chemicals. We can pick broad-spectrum preservatives and be safe at the same time.

Hydrous=containing water Anhydrous=without water

Any formulated product that contains water will need a preservative. This encompasses any water-based product that contain hydrosols or floral waters, aloe vera, as well as any product that might come into contact with water such as consumers’ hands/fingers (consider a product like a sugar scrub, that may not contain water itself, but will likely get water into it).

*Hydrosols alone do not need a preservative, but they do not last indefinitely, store them properly in the fridge to extend their shelf life. To keep bacteria out of your hydrosols, do not touch the primary bottle with your hands or applicator; instead pour what you want into another container before doing your formulating. This will greatly reduce your risk of cross-contamination.

If you are making product at home (not to be sold), you could make it in very small batches to use as quickly as possible to avoid spoilage. Always remember, you cannot go by sight like you sometimes can in looking for spoilage in a hydrosol, so use products without preservatives at your own risk (use up in less than one week). If you are selling product, you have a responsibility for the safety of your community to add one, and to choose the safest, most appropriate one possible.

Are There Natural Preservatives?

Many say the short answer is, no (but there are a few). There are however, many misconceptions to what qualifies as a preservative. Before we get to what we can use safely, let’s cover what some are erroneously using as a preservative.

GSE (Grapefruit Seed Extract)

GSE is derived from the pulp and seeds of the grapefruit. GSE is an antioxidant containing: vitamin C, citric acid, flavonoids, phytosterols, and tocopherols…. but do not mistake it for having “appropriate” preservative properties. Here is a great link that covers why it can be misunderstood, I recommend reading the studies within (1).

GSE does have its place in formulations, but on its own, will not keep the nasties out of your product.

Vitamin E

Vitamin E is not a preservative for hydrous product. It is an anti-oxidant that can help retard rancidity of fatty vegetable oils. It will not, however prevent microbial growth. Vitamin E would be ideal in an anhydrous product such as a body butter made with carrier oils/essential oils, as it will slow the rancidity of the carrier oil (remember they have a shelf life too).

Citric Acid

Citric acid, like vitamin E, is an antioxidant that can help retard rancidity of fatty vegetable oils. Citric acid is tricky though as it will change the pH of your product, making it slightly more acidic (more on pH in a little bit).

Witch Hazel Hamamelis virginiana

Witch hazel is rich in antioxidants, great for most skin types, and is astringent and hydrating in nature. Witch hazel typically contains 15% alcohol (alcohol content). In order for “alcohol” to be a true preservative giving it sufficient anti-bacterial ability, you would need to use upwards of 20% pure alcohol (you can also find alcohol-free witch hazel on pharmacy shelves) (2). This may be sufficient for a room spray but would ultimately be a very costly room spray. I would not recommend using this percentage of alcohol on the skin as it will be “extremely” drying and can cause skin irritation if not mixed with a very skin nourishing base.

Rubbing alcohol, hand sanitizer, and disinfecting pads typically contain a 60–70% solution of isopropyl alcohol in water to be effective, according to the WHO (World Health Organization) (3).

Therefore, witch hazel, with a mere 15% alcohol content, mixed with water is not a proper, effective preservative.

Essential Oils

Essential oils themselves are sometimes touted as preservatives. Let’s look at why that is not effective:

According to a study done in 2012 by frontiers in microbiology, “The main obstacle for using essential oil constituents as food preservatives is that they are most often not potent enough as single components, and they cause negative organoleptic effects when added in sufficient amounts to provide an antimicrobial effect” (4). When taking the statement of essential oils being ineffective in food preservatives into consideration, you can reasonably conclude that you would likely need to use more than would be considered safe to apply topically in order to be effective.

*It is also important to note that what is actually being used as preservatives in food such as in meats and coating for food packaging films in the food industry is actually a CO2 extract, which is extracted differently than the essential oil counterpart, and is therefore, different in it’s chemical makeup.

Do not rely on an essential oil to provide you with the preservative properties that would be necessary in a hydrous product.

 

 

A Peek At pH

What is pH? Our skin is covered in a fine film, which is called the acid mantle. This film measures anywhere from a pH of 4.7 to 5.9 (5). This measures the acidity or alkalinity of our skin, and plays a part in our cosmetics as well. As seen in the chart below, anything below 7 is acidic, and anything above 8 is alkaline.

 

 

If your skin deviates too much from this pH range, you may see an increase in scaling, a decrease in hydration due to transepidermal water loss (a measure of the amount of water that passes from inside a body to the outside via the epidermis, the skin’s topmost layer) (6), a decrease in stratum corneum protective lipids; essentially an overall inability to protect our skin.

Our skin care products should have an average pH range of 4.7 to 6 (to be as close to the pH of the acid mantle as possible). The acid mantle is an effective form of protection, but again if your pH level is consistently too alkaline or too acidic, the mantle is disturbed and skin conditions such as dermatitis, eczema, and rosacea can develop.

Let’s look at an example. Cleansers, such as bars of soap and detergent soap tend to be very alkaline in nature, and will be incredibly drying to the skin; the main reason why you have heard do not wash your face with soap, or even over wash. Therefore, using a cleanser that is slightly acidic will cleanse the skin and will not be too drying in the process.

A Brief Look At Four Preservatives

Optiphen Plus

Optiphen Plus is my go to preservative for hydrous
products. Optiphen Plus works best for a product with a pH under 6.0 (acidic). It is paraben free. This preservative is effective against bacteria, yeast, mold, and fungus and is suitable for water containing products.

PROS– Paraben free for those that are sensitive. Broad-range preservative.
CONS-pH range is limited. May not be suitable for products that are more alkaline in nature (soap).

Germall Plus

Germall Plus is my second choice. It is a broad spectrum, paraben free preservative. It is suitable for a wide pH range, so a little less guesswork in this preservative. Germall Plus is not particularly heat stable so be sure to add during the cooling down phase of your formulating.

PROS– Paraben free for those that are sensitive. Suitable for a wide pH range.
CONS– Not heat stable.

Phenonip

This is a preservative that is suitable for anhydrous product (not many are). Phenonip does contain parabens for those that are sensitive to them, but it is a powerful broad spectrum preservative. Like Germall Plus, it is suitable for a wide range pH range (7).

PROS– Suitable for hydrous and anhydrous product. Suitable for a wide range of pH levels.
CONS– A little challenging to work with when making lotion, have to separate during oil and water phases.

Geogard Ultra

Geogard Ultra is a broad spectrum preservative. It contains no parabens or formaldehyde releasers, so it is considered “natural”. It contains gluconolactone, and sodium benzoate. This comes in a powder but can be mixed with water then added to your product in the heated water phase or cool down phase. It is however, pH sensitive to a range of 3-6 (8).

PROS– Paraben and formaldehyde free. Can add to either phase of product making (heat or cool).
CONS-Some have stated that it’s effectiveness wanes so does not provide protection much past one year. Formulating at the higher end of the dosage recommendation is likely key.

Determining The pH Of Your Product

If you own a business and make cosmetic products with intent to apply to the skin AND are using water, you need to be aware of the pH of your product. Enter litmus pH indicator test strips. You can find them easily with a Google search and can test your product, determine the pH, then use the appropriate preservative. Always follow container instructions.

Risks of Not Using a Preservative

Some have asked, what are the risks of a product containing no preservative? If we allow the microbes, yeast, and fungus to grow in our product, what are the real risks? If you have a cut on your skin, you are now incredibly vulnerable to infection by using the product topically. This can mean anything from blood poisoning, yeast infection, cellulitis, staph or MRSA. The perceived benefit of being “natural” does not outweigh the very real risks.

What Increases Rate of Spoilage?

Much like essential oils: sunlight, oxygen, heat, moisture and bacteria from your fingers can all be detrimental to your products.

Practice GMP (Good Manufacturing Practices) when making product. Be sure your hands, work surface, and utensils are clean and sterile. Boil storage containers and wear protective clothing. This includes nitrite or vinyl gloves, hair net, facemask, eye protection, and lab coat (9). This will help ensure that you do not introduce bacteria or contaminate your batch. Commercial skin care production always follows GMP practices for this same reason.

Store your products in dark, airtight containers to limit exposure to air, which increases rates of oxidation. Avoid heat. Do not dip your fingers into your product; use a clean spoon or another appropriate utensil.

Closing

The use of preservatives is essential to prevent product contamination in any product containing water. As you can now see, the perceived risk does not outweigh the benefit. Be sure to read labels before purchasing product, and if the label says “preservative free” and contains water, leave it on the shelf. If you are making product at home and have more questions, feel free to email aromatherapist@planttherapy.com.

 

 References

(1) Preservatives: Grapefruit seed extract (GSE) is NOT a preservative. Retrieved from http://swiftcraftymonkey.blogspot.com/2010/10/preservatives-grapefruit-seed-extract.html

(2) Essential Oils in Food Preservation: Mode of Action, Synergies, and Interactions with Food Matrix Components. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3265747/

(2) Preservation of Cosmetics Retrieved from http://www.makingcosmetics.com/How-to-Preserve-Cosmetics_ep_58.html

(3) Alcohol. Retrieved from http://cosmetics.specialchem.com/tech-library/article/alcohol?id=1424&or=s192994_101_1424&q=alcohol+%2bpreservative

(4) Guide to Local Production: WHO-recommended Handrub Formulations. Retrieved from http://www.who.int/gpsc/5may/Guide_to_Local_Production.pdf

(5) Understanding the Acid Mantle. Retrieved from http://thenakedchemist.com/understanding-the-acid-mantle/

(6) Everything You Wanted to Know About Transepidermal Water Loss (TEWL). Retrieved from http://blog.pharmacymix.com/everything-you-wanted-to-know-about-transepidermal-water-loss-tewl

(7) Preservatives: Liquid Germall Plus. Retrieved from http://swiftcraftymonkey.blogspot.com/2010/10/preservatives-liquid-germall-plus.html

(8) Webb, M. (2015) Aromatic Medicine, Integrated Advanced Essential Oil Therapeutics for Common Clinical Conditions (Slide 216)

(9) Webb, M. (2015) Aromatic Medicine, Integrated Advanced Essential Oil Therapeutics for Common Clinical Conditions (Slide 181)

Leslie Moldenauer, CHNC, HHP, Certified Aromatherapist, has been studying natural living and holistic wellness for over 10 years. Leslie is a trusted resource that covers essential oil safety and encompasses all that natural living has to offer.  She is passionate about providing education and tools to help others make decisions regarding safety above all things when utilizing aromatherapy in the home.

23 thoughts on “Preservatives…When Are They Necessary”

  1. Thank you for this great explanation. I am just starting to get into DIY products and have been leery due to lack of info on preservatives. I just purchased some Optiphen plus to use for the few products I want ot make that use water… dishwasher tablets, foaming hand soap, etc.

    1. Optiphen plus is a great preservative, but not the best choice for a product that has a higher pH (alkaline) like soap. The pH of soap sits somewhere around 9-10 and the pH recommendation for Optiphen plus is under 6.0. If you want to test your product before adding the preservative using litmus paper pH strips that will help to tell you which one you should use.

      Warmly,

      Leslie

  2. Thanks for a great article! But what about Polysorbate 20? I have it but have not used it yet. Would love some feedback on it. Thanks!!

    1. Polysorbate 20 is a surfactant and emulsifier. That means it’s used to help “disolve/blend” the essential oils with other products. It is not a preservative.

    2. Poly 20 is not a preservative. Polysorbates are emulsifiers, wetting agents, and solubilizers. We can use them to emulsify essential oils into water, and it works well, but a preservative is still necessary.

      Hope that helps Suzette!

      Warmly,
      Leslie

      1. Hi Leslie, does that mean we don’t need poly 20 and we can just use Optiphen plus instead for say, EO sprays?

        1. Hi Jeannette. Sorry for the delayed response, I missed your question the first time. For essential oil room sprays poly20 wound not be “needed”. The Optiphen Plus with water, hydrosols, and oils will be sufficient.

          Warmly,
          Leslie

  3. Leslie Moldenauer thank you! Thank you! I appreciate your thoughtful, informative and helpful article on this topic. It is an issue we see questioned again and again in the industry. It great to be able to refer those questioning the topic to this article. It’s such an important safety topic that needs a ton more coverage in the EO industry. Thank you again.

  4. I’ve been using Leucidal sf complete (lactobacillus ferment and coconut fruit extract) in my lotions and it’s all natural but have to use at least 4%. It’s more expensive than other preservatives but I try to make products with healthy ingredients. I make lotions for my family and sell to friends. Haven’t had them tested but if I don’t go below the 4% I don’t see any nasties growing but wonder if anything is in there I can’t see…

    I also wanted to comment on GSE… I had always read that it isn’t a preservative but recently found on aromatics international’s website that they sell lotion that only uses GSE as their preservative. I’m confused by that and wondering how they keep it from going bad. They sell this as a base for adding your own essential oils. What are your thoughts on that? Thx

    1. I have not used this particular coconut extract, but can say you absolutely can have things growing in the product that is not visible to the eye, so use caution.

      I can recall someone asking AI in regards to their lotion in the past. I “think” they stated it is only for short term preservation and would need more added to it if making products from it. But to be sure, I would reach out to them and ask. Thanks Frann!

    1. Hi Sharon,

      This is not a simple answer. First you have to look at the pH of your product. This alone will determine what options you have. From there you have to consider if you have sensitive skin and are prone to react to parabens or not (both Optiphen plus and Germall plus are paraben free). Geogard ultra could be a great choice if this is a home use product to be used up in a shorter amount of time. Hope that helps, thanks Sharon.

  5. Making foaming hand soaps… and want to try body wash too… using Castile oil and EO
    just ordered my first batch of essential oils and wanted to know if those things need a preservative
    I saw the line about mrsa and other infections and almost got scared back to using the products that contain edta and all the propylene glycol and other horrific cancer causing mess 🙁

    1. Rebecca for a foaming hand soap or anything you are adding water to it is necessary to use a preservative.

  6. Which preservative would you recommend for liquid or foaming soap recipes that contain castile soap, distilled water, and carrier/essential oils? One of the recipes on the sites for foaming hand soap calls for Optiphen Plus, but then the statement was made in this article that it might not work well with soaps. I’m a little confused.

    1. Sarah,

      My apologies for any possible confusion. It can be tricky with soap as I mentioned in the article. There is a chance that the Optiphen Plus will be sufficient, but you would need to be able to test your product to be sure. If you do not have that ability to do that at present, my suggestion would be to use Germall Plus.

      Warmly,

      Leslie

  7. Hello I have a question, I am currently trying to make hair products such as shampoos, conditioners, and leave- ins to sell. I bought Neodefend (Geogard Ultra) preservative, however doing more research they are saying that it doesn’t work well with oil. I am using water and oil based products and I use BTMS-50.

    I noticed that one batch I made became mold and I really would like some information on how I can further prevent that. Should I use a clear bottle or a dark container? When and how should I use the PH strips to determine the PH balance? Do you think I can continue to use Neodefend or should I use Optiphen Plus?

    HELPP PLEASEE lol !

    1. I am sorry that you are having molding issues with your product. Use your pH strips when the product is complete (minus preservative) to help to determine which pH would best be suited to your product. All three items that you are making (shampoo, conditioner, leave-in) are very likely to all have differing pH levels.

      Geogard Ultra is best suited to a pH range of 3-6. Your shampoo will likely be much more acidic and out of that range. It is important to note that Optiphen is also best in a lower pH level (under 6), but is touted as providing stability long term. I would choose Optiphen over Geogard.

      Let me know if you need any further assistance,

      Leslie

  8. Love the Article and Feedback you provided. My question is this, I am considering adding distilled water and/or high proof vodka to various essential oils & fractionated coconut oil that I will use as an insect repellant spray. If I used the coconut oil and water (and Solubol) at 1:1 ratio, how much vodka should I use to act a sufficient preservative?

    Thank you very much!! 🙂

    1. Hi Brian. I am glad that you enjoyed the article. In order for alcohol to be a true preservative giving it sufficient anti-bacterial ability, you would need to use upwards of 20% pure alcohol in your formula.

      If “not” using the Solubol, the proof would need to be 95% to truly disburse the essential oils properly. Solubol should be minimum 3:1 (oils to Solubol), but the manufacturers recommendation is usually 4:1.

      Hope that helps!
      Warmly,

      Leslie

      1. Hi Leslie. Thank you very much. However, I just added 40% unfractioned coconut oil, 40% distilled water, and 20% 100 proof vodka. However, the oil is still separated…even after adding a bit more vodka, too. Is there something else I can do beside getting Solubol? It looks like it’s necessary to me.
        Thank you, again.
        Brian

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