Question to the Department for Environment, Food and Rural Affairs:

To ask the Secretary of State for Environment, Food and Rural Affairs, what the legal limit is for emissions of (a) PM 0.1 and (b) PM 1 particles; and what guidance his Department has issued on those emissions.

There is no legal limit for PM0.1 and PM 1 particles, However, new Euro standards for diesel vehicles limit emissions for both the total particle mass as well as the number of particles emitted per kilometre. Particle number is a common measurement technique for assessment of smaller sized particles such as PM_0.1 and PM_1.

In addition, our National Atmospheric Emissions Inventory (NAEI) provides estimates of emissions from a wide range of man-made sources and includes estimates of PM_0.1, PM₁ as well as PM_2.5 and PM₁₀. The NAEI is updated on an annual basis and is publically available at: http://naei.beis.gov.uk/