Personal care products like hand soaps, body wash, makeup, lotion, and toothpaste all rely on surfactants for various functions. This includes acting as detergents for cleaning, foaming agents for bubbles and lather, or emulsifiers to stabilize products and keep them well mixed.
Growing awareness surrounding product sustainability and safety has shone a spotlight on the chemicals and ingredients that are used to manufacture these products. This resulted in a shift away from petroleum-derived surfactants for personal care products to those derived from plants (particularly palm and to a lesser extent coconut).
However biosurfactants, or microbial-derived surfactants, represent the most sustainable option for personal care and cosmetics: high performance natural ingredients with a reduced environmental footprint.
Petroleum and palm oil-derived surfactants currently dominate the market
Currently, most surfactants are derived from oils that come from the Earth (petroleum) or from plants (like palm and coconuts). Some of these synthetic surfactants are commonly found in detergent and soap products, including sodium coco sulfate (SCS), sodium lauryl sulfate (SLS), and sodium laureth sulfate (SLES).
Unfortunately in addition to the negative environmental impact associated with their production, many of these surfactants have been reported to cause allergic reactions and skin irritation, and often require careful formulation to reduce skin irritability. One study conducted by Leoty-Okombi et al. (2020) demonstrated the potential for SLS to cause skin dryness, redness, and irritation through a 24 hour skin patch test with female participants.
Benefits of Biosurfactants
In contrast with many widely used synthetic surfactants, biosurfactants possess properties that make them advantageous for use in skin and personal care products, including improved biodegradability, low toxicity, versatility, and surface moisturizing characteristics.
Low Environmental Impact & Biodegradability
Many of the negative environmental impacts of the current chemicals used in our products – in both production and environmental impact, can be mitigated with the adoption of biosurfactants. As the name suggests, biosurfactants are surfactants derived from biological organisms, typically microbes like yeast, fungi, and bacteria. Being derived from living organisms, biosurfactants are 100% natural, biodegradable, and renewable! Biodegradation tests in a study by Hirata et al (2009) demonstrated improved biodegradability of sophorolipids over 8 days as compared to other synthetic surfactants including linear alkylbenzene sulphonate (LAS) – a common surfactant used in household detergents.
Biosurfactant production in laboratory bioreactors eliminates the dependency on large plantations for chemical production, which are associated with deforestation and increased greenhouse gas emissions (GHG). The production of biosurfactants also eliminates the risk of dioxane contamination in personal care and cleaning products. The synthesis reaction of common surfactants from petroleum of palm-oil (e.g. SLES) results in the production of 1,4-dioxanes as a by-product, which has been identified as an environmental contaminant and potential carcinogen.
Low Toxicity and Skin Compatibility
Biosurfactants are not only biodegradable, but are also more efficient and less irritable when they come in contact with our skin. A study by Farias et al. (2019) discovered that mouthwashes containing the microbial surfactants, represented lower toxicity than the commercial counterparts after formulating several types of mouthwash with a biosurfactant.
The improved biocompatibility of biosurfactants is, in part, due to the similarity of their chemical components (sugars, lipids, and proteins) to the molecules in our own skin. The structure of biosurfactants further allows for easy skin penetration and high permeability that can trigger cellular protective responses. In contrast, SLS – one of the most common synthetic surfactants found in personal care products – can irritate and dehydrate our skin, disrupt the proteins necessary for our skin to act as a barrier to the outside world, and disturb our skin microbiota.
High Stability, Efficiency and Activity at Extreme Conditions
Perhaps one of the most unique characteristics of biosurfactants is their ability to be effective at extreme conditions, including high pH and temperatures. This allows their critical micelle concentration (CMC) to form with a lower amount of surfactant added, demonstrating their heightened efficiency as compared to chemical surfactants. In many cases, biosurfactants’ CMC value is 10-40 times lower than that of synthetic surfactants.
References and Further Reading
- Adu SA, Naughton PJ, Marchant R, Banat IM. Microbial biosurfactants in cosmetic and personal skincare pharmaceutical formulations. Pharmaceutics. 2020 Nov;12(11):1099. https://doi.org/10.3390/pharmaceutics12111099
- How companies are getting 1,4-dioxane out of home and personal care products (Bettenhausen, 2020): https://cen.acs.org/business/consumer-products/companies-getting-14-dioxane-home/98/i11
- De S, Malik S, Ghosh A, Saha R, Saha B. A review on natural surfactants. RSC advances. 2015;5(81):65757-67. https://pubs.rsc.org/en/content/getauthorversionpdf/c5ra11101c
- Farias JM, Stamford TC, Resende AH, Aguiar JS, Rufino RD, Luna JM, Sarubbo LA. Mouthwash containing a biosurfactant and chitosan: an eco-sustainable option for the control of cariogenic microorganisms. International journal of biological macromolecules. 2019 May 15;129:853-60. https://doi.org/10.1016/j.ijbiomac.2019.02.090
- Hirata Y, Ryu M, Oda Y, Igarashi K, Nagatsuka A, Furuta T, Sugiura M. Novel characteristics of sophorolipids, yeast glycolipid biosurfactants, as biodegradable low-foaming surfactants. Journal of bioscience and bioengineering. 2009 Aug 1;108(2):142-6. https://doi.org/10.1016/j.jbiosc.2009.03.012
- Moldes AB, Rodríguez-López L, Rincón-Fontán M, López-Prieto A, Vecino X, Cruz JM. Synthetic and bio-derived surfactants versus microbial biosurfactants in the cosmetic industry: an overview. International Journal of Molecular Sciences. 2021 Jan;22(5):2371. https://doi.org/ 10.3390/ijms22052371
- Olasanmi IO, Thring RW. The role of biosurfactants in the continued drive for environmental sustainability. Sustainability. 2018 Dec;10(12):4817. https://doi.org/10.3390/su10124817