In early 2000s, Proventia operated under the name Finnkatalyt. The company focused more and more on cleaning diesel emissions and had been conducting serious research into effective particulate removal devices for the previous couple of years. As Hong Kong's Environmental Protection Department (EPD) published a tender to install exhaust purifiers in heavy-duty diesel vehicles, Finnkatalyt was ready to participate.
The company won the tender in four of five categories to supply catalytic devices (based on DOC technology). Installations started at the end of 2002. During 2003 Finnkatalyt received additional business in different vehicle classes. In 2004, tendering covered special application vehicles with long idling times, such as mobile cranes and concrete mixers, and Finnkatalyt became the sole supplier for the project. In 20022005 tens of thousands of devices were successfully installed.
Since 2012 Proventia has delivered over a hundred NOxBUSTER® systems to Hong Kong. These systems are retrofitted to EURO 2/ 3 double-decker buses, upgrading the vehicle to Euro 5 emission class.