In the air quality directive (2008/EC/50), the EU has set a target value and a long term objective value for ozone (O3) for the protection of human health. Target value: the maximum daily eight-hour mean may not exceed 120 micrograms per cubic metre (µg/m3) on more than 25 days per calendar year averaged over three years. Long term objective value: the maximum daily eight-hour mean may not exceed 120 micrograms per cubic metre (µg/m3) within a calendar year.
EEA standard re-use policy: unless otherwise indicated, re-use of content on the EEA website for commercial or non-commercial purposes is permitted free of charge, provided that the source is acknowledged (http://www.eea.europa.eu/legal/copyright). Copyright holder: European Environment Agency (EEA).