Do I Need To Use A Preservative In My Aromatherapy Product?

by Jade Shutes

Let’s talk aromatherapy and preservatives

Preservatives and aromatherapy body care products seems to be one of the hot topics in the aromatherapy community these days and one that deserves a bit more exploration.

Firstly, it may be beneficial to reflect upon the origins of ‘holistic aromatherapy’. Holistic aromatherapy was, and is, a practitioner-based and client-focused practice. Within this context, most ‘aromatherapy practitioners’ were and are making small batch products customized to a client and designed to be used up within 1-3 months.

The home user and the professional aromatherapy practitioner making small batch aromatherapy body care products designed to be used within a 1-3 month period do not necessarily need to be using preservatives, as long as simple guidelines are followed and it is understood that these products have a short shelf life and need to be stored in cool conditions. (See ‘Simple Steps to Ensure Your Homemade Cream/Lotion is Safe’ link)


What Aromatherapy Products may need Preservatives?

If you are manufacturing botanical body care or aromatherapy emulsions that require shelf stability or may be sitting around in your home for more then 6 months, you most likely should be using some kind of preservative system along with ‘hurdle technology’.

Aromatherapy and Botanical Body Care Product formulators basically make four types of products:

1. Anhydrous products: These are cosmetic and skin care formulations that use only oil-based ingredients and do not contain water. These products do not need to have a preservative added to them. The caveat is: if the product is one that will be exposed to water, then it may need a preservative (e.g. facial scrub, see #4).

2. Oil-in-water or water-in-oil emulsions: These two both represent the concept of water + oil. As you know, water and oil (or essential oil) don’t mix. So why do we want to combine them? When we combine (emulsify) oil and water (or water and oil), we are able to create beautiful creams and lotions as well as some cleanser and gel formulations. (NOTE: If making small batch aromatherapy products you have a choice to preserve, if, however, you are formulating for a product line that you hope to get into stores or you will have on a shelf for any length of time, then it is very important to preserve creams, gels, cleansers, and lotions!)

3. Water/hydrosol based products: e.g. toners, facial mists, linen or room sprays (**NOTE: We do not recommend using preservatives in linen or room sprays, nor in some toners. With toners, it depends on the ingredients used. So some formulations may need to have a preservative, such as Leuconostoc/Radish Root Ferment Filtrate). There are ways of formulating this category of products so that a preservative is not needed.)

4. Products that may be exposed to water during use: facial and body scrubs, cleansers. (**NOTE: We do not recommend using preservatives in salt scrubs. We do recommend vegecide for facial scrubs. Consider taking our Botanical Body Care Products certification course to advance your knowledge!)


What is a Preservative?

Preservatives are defined as ‘substances which are exclusively or mainly intended to inhibit the development of micro-organisms in the cosmetic product’. (REGULATION (EC) No 1223/2009 OF THE EUROPEAN PARLIAMENT AND OF THE COUNCIL, Article 2, 1L, 2009)

The most ideal cosmetic preservatives will offer a broad spectrum of antimicrobial activity covering gram-negative and gram-positive bacteria as well as fungi, yeast, and mold. To accomplish this goal, ‘green’ preservatives and preservative-enhancing ingredients may need to be used. We also recommend the use of ‘hurdle technology’ to further ensure product stability.


Why Preservatives are Used:

Preservatives are additives used to increase the shelf life of a product and to protect consumers from microorganisms that could potentially cause infection. The need for a longer shelf life grew out of the global expansion of the food and cosmetic market, to make sure the product maintained its fresh just-made appeal — even after many months (and sometimes years) of sitting on a shelf and traveling across the globe.

Preservatives are most importantly used to protect us against microorganisms that could potentially make us ill. These pesky microorganisms exist in nature and in our bodies, and, in general, we co-exist peacefully with them. However, there are some that can cause us to become quite ill if they are provided an environment where they may grow out of control, making it important for us to protect ourselves against them. Preservatives maintain cosmetic formulations ‘microbiological purity during manufacture, packing, storage, and during their lifespan of use by the consumer’ 1.

Key concerns regarding microbial contamination of cosmetics are for those cosmetics that will be applied around the eyes, on mucous membranes, on damaged skin, on children under 3 years of age, on elderly people, and with individuals with a compromised immune system. All of these ‘conditions’ mean that any microbial contamination could be detrimental. Preservatives are used, therefore, to prevent infections in vulnerable areas of the body (e.g. on damaged skin, in the eyes – an infection in the eyes could lead to blindness) and to prevent infections in vulnerable populations.

Please remember: preservatives are only needed when water is being used within the cosmetic formulation. Water is necessary for microbial growth to occur.

For cosmetic formulations, the best type of water to use is distilled or purified water.
We do not recommend using tap water, even for room sprays.


What preservatives protect us from:

Preservatives are used to prevent bacteria, mold, or yeast from occurring in cosmetic products applied to the skin. Studies have shown that the most frequently found microorganisms in cosmetics are Pseudomonas aeruginosa, Klebsiella oxytoca, Burkolderia cepacia, Staphylococcus aureus, Escherichia coli, Candida albicans (a yeast), Enterobacter gergoviae, and Serratia marcescens, but also other bacteria, fungi, and yeasts.2 Mold and yeast are types of fungi. The body of the mold spreads throughout the growth medium, in this case the cosmetic, and only the fruiting body, which produces the spores, is visible on the top. The most common yeast being Candia albicans. (Note: the microorganisms in bold are considered to be the primary microorganisms of concern to the cosmetic industry. Secondary microorganisms include any gram-negative bacilli, Enterococcus species, and Mold species.)

To prevent mold, yeast, and bacteria from contaminating a product, the length of exposure to water, oxygen, nutrients, and temperature must be controlled.

It is also important to recognize that the distinction
between what we consider to be harmless flora or a pathogenic
agent often lies in the skin’s capacity to resist infection,
and not the inherent properties of the microbe.3

How Microorganisms Get into Cosmetics

Remember, cosmetic firms are legally responsible for making sure their products are safe. Some of the ways cosmetics may become contaminated with bacteria or fungi are:

  • Contaminated raw materials, water or other ingredients
  • Poor manufacturing conditions
  • Ingredients that encourage growth of microorganisms, without an effective preservative system
  • Packaging that doesn’t protect a product adequately
  • Poor shipping or storage conditions
  • Consumer use, such as the need to dip fingers into the product4

Preservatives to consider include:

 

NOTE: We have only listed preservatives that are approved by COSMOS or EcoCert (unless otherwise noted) or commonly found in more natural skin care lines. It should also be noted that preservative choice is often dictated by consumer demand. The current trend is for either preservative-free products (rare in mass market products) or more ‘natural based’ preservative systems.


1. Leucidal® Liquid

  • INCI: Leuconostoc/Radish Root Ferment Filtrate
  • **Additional preservative enhancer needed. Recommend to use with: Sodium benzoate and Potassium sorbate OR AMTicide® Coconut
  • Green Certifications: Ecocert – approved as an ingredient in organic cosmetics
  • Recommended Usage Level: 2.0% – 4.0%
  • pH range: 4.0 – 6.0

Supplier: http://www.theherbarie.com/Leucidal-Liquid.html


2. Geogard 221

  • INCI: Benzyl Alcohol & Dehydroacetic Acid
  • Green Certifications: COSMOS , Ecocert , NaTrue Certified
  • Recommended Usage Level: 0.2 – 1%
  • pH range: Wide effective pH range – pH 3.0 – 6.0, can be inactivated by nonionics

Information:

Suppliers:


3. NatureCide – Aspen Bark Extract

  • INCI: Populus tremuloides (Aspen) Bark Extract
  • **Needs additional preservative enhancer. Recommend: P Anisic Acid
  • Recommended Usage Level: 0.2 – 3%
  • pH range: Wide effective pH range – 3.0 and 9.0

Suppliers:
www.fromnaturewithlove.com/SOAP/product.asp?product_id=PRESEXTASPBRKWSPUS725
http://www.ingredientstodiefor.com/item/NatureCide_Aspen_Bark_Extract/397


4. P Anisic Acid

  • INCI: P Anisic Acid
  • **Needs additional preservative enhancer. Recommended: Populus Tremuloides (Aspen) Bark Extract
  • Recommended Usage Level: 0.05–0.3%
  • pH range: pH of between 4.5–5.5

5. Geogard ECT

  • INCI: Benzyl Alcohol & Salicylic Acid & Glycerin & Sorbic Acid
  • Recommended Usage Level: 1.0%
  • pH range: Wide pH compatibility: (pH 3.0 – 8.0)

Supplier: http://www.voyageursoapandcandle.com/Geogard_ECT_Preservative_p/62453.htm


Other Preservative Enhancers: ingredients that can boost core preservative

• Leucidal® Liquid SF (use in conjunction with Leucidal)
INCI Name: Lactobacillus Ferment

Supplier: The Herbarie


• Sodium Benzoate (http://www.theherbarie.com/Sodium-Benzoate.html)
INCI Name: Sodium Benzoate
Effective when used in products with pH 4.5 or less.
*Typically used in combination with Potassium sorbate.

Supplier: http://www.theherbarie.com/Sodium-Benzoate.html


• Potassium Sorbate
INCI Name: Potassium Sorbate
Effective up to pH 6.5, but is more effective as the pH decreases and becomes more acidic, best at pH of 5.0.
*Typically used in combination with Sodium benzoate.

Supplier: http://www.theherbarie.com/Potassium-Sorbate.html


For products such as facial and body scrubs.

• Vegecide (http://www.ingredientstodiefor.com/item/VegeCide/925)
INCI:Glyceryl Monocaprylate (and) Glyceryl Monoundecylenate

Supplier: http://www.ingredientstodiefor.com/item/VegeCide/925?category=32


Other Ingredients that serve as Preservative Potentiators

Raw ingredients may also serve as preservative potentiators, thereby increasing or enhancing the antimicrobial activity of the main preservative. Some of these ingredients include: nonionic surfactants (see Important Aspects below for a listing of nonionic surfactants), antioxidants, Caprylyl glycol, ethanol, caprylic/capric glycerides, glycerin, and essential oils.


How to use Preservatives

Working with preservatives requires a full understanding of each preservative and it’s requirements for being used in the formulation.

Important aspects include when looking for a preservative include:

  1. the pH of product: e.g. benzoic acid exhibits antimicrobial activity only when the pH is below 5.0; dehydroacetic acid remains active up to a pH of 7.0; anisic acid is effective when pH is below 5.57; sodium benzoate, potassium sorbate, and sodium dehydroactate are only effective when used in products with an acidic pH.
  2. the compatibility of the preservative with other ingredients being used in the formulation (e.g. Geogard 221 may be inactivated when used with nonionic surfactants: ‘polysorbates, emulsifying wax NF, e-wax, glyceryl oleate, glyceryl stearate, and ingredients with the prefix PEG, ceteareths, oleths, sorbitans, lauryl glucoside, and polyglycose’8.),
  3. the solubility of the preservative (most preservatives are water soluble),
  4. the temperature of the ‘water’ when preservative is added (most preservatives are added directly into the water prior to emulsification or to the emulsified product during the cool-down phase). Be sure to read up on the preservative you are using to see if there are temperature concerns. If using phenoxyethanol, high temperatures could cause evaporation of the preservative (hence always add in cool down phase!).
  5. the need for citric acid: If using sodium benzoate, potassium sorbate or sodium dehydroacetate, you may need to add in citric acid to reduce pH into range needed for these preservatives to be effective.

Calculating for Preservatives

If you decide to add preservatives to your creams and lotions, it is important to calculate based upon weight and not volume. In Botanical body care product manufacturing, all ingredients are weighed. This is the only way to properly ensure that the correct amount of preservative is being used. Safety and efficacy are based upon weight measurements of a given preservative within a cosmetic formulation.


Are there issues with preservatives?

Yes! Preservatives are second to fragrance in causing skin irritation, skin sensitization, and allergies.6 And with newer information on the skin microbiome, preservatives may actually destroy not only pathogenic bacteria but also commensal bacteria. This is one of the reasons we, at the School for Aromatic Studies, do not recommend the use of optiphen or other phenoxyethanol-based preservatives in aromatherapy or botanical body care products. Phenoxyethanol is not approved by COSMOS or EcoCert as a preservative in organic or natural cosmetics/body care products.

Articles – Food for Thought:


Advance Your Skills and Knowledge of
Aromatherapy Product Formulation!

If you are interested in advancing your botanical body care formulations or aromatherapy products, consider our
Botanical Body Care Products Certification course!

References

  1. Herman, A., Herman, A.P., Domagalska, B.W., Miynarczk, A. (2013). Essential Oils and Herbal Extracts as Antimicrobial agents in Cosmetic Emulsion. Indian J Microbiol 53(2): 232-237. DOI: 10.1007/s12088-012-0329-0.
  2. Neza, E. and Centini, M. (2016). Microbiologically contaminated and Over-Preserved Cosmetic Products According to Rapex 2008-2014. Cosmetics 3(1), 3; doi:10.3390/cosmetics3010003 Retrieved from: http://www.mdpi.com/2079-9284/3/1/3/htm
  3. Cogen, A.L., Nizet, V., Gallo, R.L. (2008). Skin microbiota: a source of disease or defence? Br J Dermatol. 158(3): 442–455. doi:10.1111/j.1365-2133.2008.08437.x. Retrieved from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2746716/pdf/nihms91877.pdf
  4. US Food and Drug Administration. (2017). Microbiological Safety and Cosmetics. Retrieved from: https://www.fda.gov/Cosmetics/ProductsIngredients/PotentialContaminants/ucm433748.htm
  5. English, D.J. (n/d). Microbiology in Cosmetics – Challenges in Cosmetic Manufacturing. Avon Products, Ind. Retrieved from: http://www.cbinet.com/sites/default/files/files/English_Don_pres.pdf
  6. Goossens, A. (2015). New Cosmetic Allergens. Cosmetics, 2, 22-32; doi:10.3390/cosmetics2010022
  7. English, D.J. (n/d). Microbiology in Cosmetics – Challenges in Cosmetic Manufacturing. Avon Products, Ind. Retrieved from: http://www.cbinet.com/sites/default/files/files/English_Don_pres.pdf
  8. Sanford, V. (2016). Using Natural Surfactants in Cosmetics. Retrieved from: http://library.essentialwholesale.com/6390-2/

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