Question to the Department for Transport:

To ask the Secretary of State for Transport, what assessment she has made of the potential impact of using bunker oil to power large ships on busy waterways on air quality.

The main pollutants affecting air quality from bunker fuels are nitrous oxides (NOx), sulphur dioxide (SOx) and particulate matter (PM). These pollutants are well understood and international regulations have been in place for several years. The International Maritime Organization (IMO) introduced regulation limiting the sulphur content of fuel in 2020, which led to an immediate 70% reduction in sulphur oxide emissions.

The IMO also has strict controls on nitrous oxide (NOx) emissions, with global limits on NOx emissions from marine engines and additional Emissions Control Areas subject to even more stringent controls. The production of particulate matter is not currently regulated by the IMO, but domestic targets were introduced under the Environment Act 2021.

Air quality is expected to improve with the switch to future fuels as part of the transition to net zero and my department will continue to develop the evidence base to understand any air quality impacts.