# The Environmental Protection (Prescribed Processes and Substances) Regulations 1991, Schedule 4: RELEASE INTO THE AIR: PRESCRIBED SUBSTANCES

Extent: E+W+S

Oxides of sulphur and other sulphur compounds
Oxides of nitrogen and other nitrogen compounds
Oxides of carbon
Organic compounds and partial oxidation products
Metals, metalloids and their compounds
Asbestos (suspended particulate matter and fibres), glass fibres and mineral fibres
Halogens and their compounds
Phosphorus and its compounds
Particulate matter.

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Source: https://www.legislation.gov.uk/uksi/1991/472/schedule/4 (the official version)
Page: https://openlegislation.uk/environmental-protection-prescribed-processes-and-substances-regulations-1991/schedule-4
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.