The objective of this project is to demonstrate rhamnolipids as functional additives for firefighting foams to displace biopersistent and bioaccumulative per- and polyfluoroalkyl substances (PFAS) which are a current environmental liability for the Department of Defense (DoD). Stepan Company's rhamnolipids are natural biosurfactants fermented using a natural production organism. They are not biopersistent or bioaccumulative and they have a very mild eco-toxicity and irritation profile. The objective of the project team, that includes participants in multiple steps of the value chain — Stepan, Perimeter Solutions, and Jensen Hughes — is to show that rhamnolipids can also provide fire-suppression performance via stable and high-quality foams in fire suppressants for military use, creating options to improve safety of DoD personnel at airfields and onboard ships.

Rhamnolipids are natural, environmentally friendly, mild yet high foaming biosurfactants. Because rhamnolipids are new chemicals currently entering the marketplace, they have not previously been tested in firefighting foams. Stepan’s rhamnolipids form dense, stable foams and they can act as foam boosters for other surfactants, both of which indicate they are promising candidates for firefighting foam. Tasks of the project include (a) formulating a rhamnolipid-based Class B firefighting foam concentrate (b) testing to ensure it will meet specifications (c) large scale extinguishment demonstrations and (d) an EcoProfile, a Life-Cycle Assessment-like approach, that quantifies the sustainability and environmental benefits of the new concentrate versus current options. The first, most critical task will be developing a formulation for a concentrate. Two approaches will be taken: (1) starting with rhamnolipids as the base ingredient and adding other functional additives to improve performance and (2) modifying existing PFAS-free formulations with the addition of rhamnolipids. A Design Of Experiment approach will be used to downselect to an optimum formulation as quickly as possible.

The benefit to the DoD is the ability to quickly and safely extinguish dangerous fires with a firefighting foam concentrate that does not have the long term negative environmental and toxicological effects of concentrates that contain PFAS. The project team is committed to sharing all learnings with military firefighters to ensure the fastest, safest and most effective extinguishment can be accomplished. The benefit to the scientific community is that a significant amount of data on rhamnolipids’ capabilities in firefighting applications will be generated and shared, and opportunities for their commercial use will be expanded.