# Air Quality Regulations (Northern Ireland) 2003, Paragraph 1: Interpretation

Extent: N.I.
Status: prospective

“PM10” means particulate matter, which passes through a size-selective inlet with a 50% efficiency cut-off at 10μm aerodynamic diameter.

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Source: https://www.legislation.gov.uk/nisr/2003/342/schedule/paragraph/1n2 (the official version)
Page: https://openlegislation.uk/air-quality-regulations-northern-ireland-2003/schedule/paragraph-1n2
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.