SootSense is developing an instrument for accurately measuring levels of hazardous black carbon in the air

Black carbon accelerates climate change and is harmful to humans, which is why its emissions are expected to be restricted. SootSense can help industries and cities in the fight against black carbon.

Clouds of soot composed of particles of black carbon are extremely harmful air pollutants (in Finnish). Accordingly, industrial black carbon emissions will likely be restricted, and the amount of black carbon in cities will be extensively monitored.

University of Helsinki researchers working in the SootSense project are developing an instrument for measuring the concentration of black carbon more accurately than before. As regulation increases, the invention can prove helpful.

“The limit values set for air pollution are useless if we can’t measure the concentrations of pollutants,” says Professor Markku Vainio, who heads the research group.

“Black carbon causes global warming and is harmful to human health. According to the World Health Organization (WHO), air pollution as a whole is annually associated with some seven million deaths, with black carbon accounting for a significant share,” notes Tommi Mikkonen, DSc, the commercialisation specialist for the SootSense team.

“When you consider the overall effects of black carbon on health and the climate, it’s fair to say that it’s the world’s most hazardous air pollutant.”

More precise measurement technology in a compact format

At present, black carbon is measured with an old technique in which an airstream is passed through a particle filter. Mikkonen says the technique is unreliable. In addition, the equipment needed is large and requires maintenance. The light-based technology developed by the SootSense team solves these problems.

“Using a laser, soot particles and the surrounding air can be made to emit a sound, which is then measured with a microphone,” says Mikkonen, explaining how the invention works.

The innovation was created at the University of Helsinki Department of Chemistry. The laser spectroscopy research group working there has long been developing ultra-sensitive analysis methods for gaseous air pollutants.

“A few years ago, we became interested in exploring whether the same methods could be used to measure black carbon,” states Vainio.

He describes the promising results they obtained from the very first experiment – better than any other technique had yielded before. In early 2023, a team of physicists and chemists received Business Finland’s two-year Research to Business funding to prepare the commercialisation of their invention.

Research organisations and industrial sectors as customers

The SootSense team believes the demand for the innovation is significant. In California a new bill aims to boost air monitoring systems near petroleum refineries, and Mikkonen says that the measurement of black carbon levels is required in parts of the state.

“It’s highly likely that similar restrictions will spread both geographically and across industries.”

This means that SootSense customers could include major corporations in Europe and North America. But first the team will seek customers in the public sector, such as research organisations building measurement networks. Mikkonen believes the market will develop gradually and, as regulation expands across industries, the commercial potential of the innovation will skyrocket.

“People have now realised that this problem causes hundreds of billions of euros in annual costs.”

The SootSense technology increases our understanding of phenomena associated with black carbon, which helps in targeting restrictions appropriately. The technology could also be used for air quality monitoring during wildfires, for instance.

Refining the product, one step at a time

The SootSense team has a pending patent application, and the technology works without a hitch in laboratory conditions. Now the goal is to offer the same capability in a commercial instrument. The Research to Business funding allows the team to continue developing the measurement technique and conducting market research until the end of 2024.

The Finnish Meteorological Institute is an important partner in refining the innovation, but to validate the technology, the team is also collaborating with other developers of new measurement technologies. Vainio lists not only precision, but also its small size among the advantages of SootSense. The instrument may also be less expensive than those of competitors.

“If each city requires several measuring stations, price plays a big role,” he notes.


Soot, or black carbon, increases global warming and causes premature mortality. As a result, efforts have been taken to restrict its emissions. However, the black carbon measuring instruments currently available in the market are not very accurate. They are also expensive and large, and require maintenance.


SootSense has developed a technology that can accurately measure the smallest concentrations of black carbon. The instrument is small, potentially inexpensive and automated. The new technology increases our understanding of phenomena involving black carbon and helps us target restrictions appropriately.

Business model

The SootSense instrument could initially be used by research institutes measuring air quality around the world. Subsequent customers could include North American and European industries where black carbon emissions are restricted. The business model will be further elaborated during the commercialisation project.

Join the collaboration

To test the innovation, SootSense is seeking collaboration partners among cities and research institutes measuring air quality. The team is also happy to enter into discussions with investors.

Contact the team

Professor Markku Vainio

Principal investigator of the SootSense project

Postdoctoral Researcher Tommi Mikkonen

Commercialisation specialist