Why are biosurfactants not used widely in commercial cleaning products?
Biosurfactants have been hailed as the natural alternative to surfactants derived from crude oil or plant-based oils in recent years. However the use of these substances has been limited to a few specialized low volume products.
Biosurfactants from plant origin have been used for laundering and personal care purposes in the past. However soap nuts have failed to show significant laundry cleaning performance under standardized scientific tests.
Two Problems: Availability and Regulatory
The hurdles for a broad use of biosurfactants are twofold.
- No biosurfactant is available in quantities high enough to seriously replace current surfactants on a large scale.
- EU Regulation, while serving its purpose, puts significant hurdles towards the industrial use of biosurfactants.
Recent advances towards the availability of biosurfactants
The industry has pursued the activities to make biosurfactants accessible to the cleaning industry. Two examples of the latest efforts shall be named.
Nouryon organizes the Imagine Chemistry contest as a way to create a more sustainable future through chemistry. Since 2017 this contest has seen winners in the field of biosurfactants:
2017’s winners Dan Derr and John Abernathy were awarded for their work on “Natural biosurfactants from fermentation”. Also the company Holiferm was founded with the aim to produce biosurfactants economically, as a result of Ben Dolman’s participation in the contest. 2019’s finalists in the section “Sustainable bio-based surfactants” include CarbExplore Research, Fraunhofer IGB, Sironix Renewables and The University of Sheffield + Entomics.
The Allianz Biotenside in Germany involves companies along the value chain and investigates the use of biosurfactants for commercial applications. It’s members are internationally active coproations such as Henkel, dalli and BASF, among others. Its goal is the commercial production of biotechnically produced biosurfactants that have been optimized towards their function.
Regulatory challenges for biosurfactants
As any chemical that is to be sold in the EU, biosurfactants need to be registered under the REACH regimen. Besides the significant cost associated with this registration, really two regulations set considerable bars for the use of biosurfactants: the Detergent Regulation and the Biocidal Product Regulation.
Detergent Regulation (DetReg)
The ancestor of today’s DetReg was conceived in the 1960ies following the appearance of foam mountains on rivers throughout Europe. Consequentially, one main aspect of the DetReg is to make sure, that surfactants used in commercial cleaning products are biodegradable.
It may sound counter intuitive, but biosurfactants may not be biodegradable enough to be used in commercial cleaning products. It is widely agreed that biosurfactants produced in nature are biodegradable to a certain extend. Otherwise we would encounter massive accumulations of these substances in nature.
In fact the purpose of biosurfactants in nature are to either access food sources or to gain a growth advantage. For either purpose a high biodegradable is undesirable as the energy used to produce biosurfactants would increase the higher the biodegradability.
Having said that, DetReg sets forth specific requirements towards biodegradability and these may be too tough for biosurfactants. Nature just did not “invent” biosurfactants with cleaning in mind.
To make things worse, scientific publications were touting the biodegradability of biosurfactants without providing relevant data, leaving a false impression in the public opinion. The promotion of soapnuts as biological detergent without the knowledge of the biodegradability of the actives involved also contributed its part to a biased public opinion.
In short
The biodegradability of biosurfactants needs to carefully checked against the requirements of DetReg. It may be too low for the use in commercial cleaning products. Also unsubstantiated claims of biodegradability and biocidal activity without relevant data do not help.
Biocidal Product Regulation (BPR)
In order to gain a growth advantage, the best way in nature is to inhibit the growth of competitors. As a result some biosurfactants display a bacteriostatic effect or even an antimicrobial/ anti-fungal effect. These effects have been described in literature and have been lauded as an added benefit versus conventionally produced surfactants.
In fact these effects may compromise the use of biosurfactants dramatically. The BPR’s goal is to make sure that no uncharacterized biocidal products are used in the EU. Besides the characterization, BPR also requires the registration and the authorization of the biosurfactants and the products containing the biosurfactants.
The registration of any chemical as a biocidal active sums up to a 6 digit Euro sum. In addition a chemical registered as a biocidal active may not be used in regular cleaning products unless it does not contribute a biocidal performance to the product. In practice lively discussions have been going on between producers and authorities to which extend a biocidal substance contributes to which biocidal activity. As a result some market players are hesitant to use substances with known biocidal effects in non-biocidal products in order to avoid aforementioned discussion.
In short
The biocidal nature of some biosurfactants hinder the their use in commercial cleaning products relevant concentrations as these would render the product a biocidal product and thus would require heavy investment in the registration and authorization of the product.
The Path Forward
Making biosurfactants attractive for the use in commercial cleaning products requires the increase in availability and a decrease in raw material prices. Significant efforts are underway and there is the opportunity to further intensify them.
Using biosurfactants in commercial cleaning products requires the full set of data to show compliance with existing regulation. The collection of this data should happen already at the point of first publication in order to avoid the creation of false hopes.
