Sensiblue Receives European and South African Patents for Flow-Powered Water Disinfection Technology
We are proud to announce that Sensiblue IP B.V. has been granted a European patent (EP4568930, granted 11 March 2026) and a South African patent (2025/00599, granted 25 March 2026) for our core water disinfection technology. Both patents cover the same invention: a method and device for disinfecting water in a water supply system through the electrolytic generation of active chlorine — powered entirely by the flow of water itself.
What makes this technology unique?
The invention solves a problem that has persisted in water disinfection for decades: how do you generate the right amount of disinfectant, at the right moment, without relying on external electricity?
The answer lies in an elegantly simple principle. A turbine generator — a small blade wheel placed in the water pipe — spins as water flows through it. This spinning generates alternating current (AC), with a frequency that is directly proportional to the flow rate of the water. That frequency signal is then used to control precisely how much active chlorine (hypochlorous acid, HOCl) is produced in the electrolytic cell. More water flowing means higher frequency, which means more disinfectant produced — automatically, proportionally, and without any external power connection.
This is the core innovation. Prior art, including earlier work by the same inventors (EP1461291), used DC generators. The new invention uses an AC generator specifically because the AC frequency carries information: it tells the system exactly how fast water is flowing, and therefore exactly how much chlorine is needed. The system is self-calibrating and self-regulating.
Why does this matter?
Access to safe drinking water remains one of the most urgent challenges facing humanity. According to the WHO, over 2 billion people lack access to safely managed drinking water. Existing electrolytic disinfection systems require grid electricity, making them unsuitable for off-grid schools, clinics, and communities in low-income countries.
Sensiblue's technology removes that barrier entirely. Because the device is powered by water pressure alone, it can operate wherever water flows — whether from a gravity-fed tank in rural Uganda, a rainwater harvesting system in South Asia, or a residential water supply in Europe.
In developed markets, the technology addresses a different but equally serious problem: Legionella. Heat pump and Low Temperature heating systems — growing rapidly across Europe as part of the energy transition — operate at water temperatures of 38–45°C, precisely the range in which Legionella bacteria thrive. Thermal disinfection at 60°C is incompatible with heat pump systems. Sensiblue's continuous residual chlorine generation at a low dose (around 0.2 mg/L) suppresses Legionella and biofilm without requiring any additional energy input. The granted patent explicitly claims use of the device for preventing Legionella in water supply systems where maximum water temperature is insufficient to prevent Legionella growth (Claim 14, EP4568930).
A 20-year protection across dozens of countries
The European patent covers all designated contracting states including Germany, France, the UK, the Netherlands, Italy, Spain, and more than 30 others. The South African grant adds coverage on the African continent. Both patents originate from PCT/NL2023/050397, filed 25 July 2023, with a priority date of 8 August 2022. Combined with 58 national patent applications filed in January 2025, Sensiblue's IP position now spans multiple continents and all major markets in the world.
From invention to impact
This technology has been in development for over two decades, originating with inventor Johannes Petrus Paulus Tholen. The granted European and South African patents represent formal international recognition that this approach is novel, inventive, and industrially applicable — and they provide the legal foundation to bring it to scale.
We are already deploying the Sensiblue S4 in schools in Uganda, residential buildings in the Netherlands, and commercial buildings across Europe. These patent grants strengthen our ability to do so with confidence — and to defend the technology against imitation as we grow.
Safe water is not a luxury. It is a right. We built Sensiblue to make that right accessible to everyone, everywhere water flows.
