For the purposes of this Directive, the following definitions apply:

1. (1)

   ‘emission’ means the release of a substance from a point or diffuse source into the atmosphere;

2. (2)

   ‘anthropogenic emissions’ means atmospheric emissions of pollutants associated with human activities;

3. (3)

   ‘ozone precursors’ means nitrogen oxides, non-methane volatile organic compounds, methane, and carbon monoxide;

4. (4)
   ‘air quality objectives’ means the limit values, target values and exposure concentration obligations for air quality set out in Directive 2008/50/EC and Directive 2004/107/EC of the European Parliament and of the Council12;
5. (5)

   ‘sulphur dioxide’ or ‘SO₂’ means all sulphur compounds expressed as sulphur dioxide, including sulphur trioxide (SO₃), sulphuric acid (H₂SO₄), and reduced sulphur compounds such as hydrogen sulphide (H₂S), mercaptans and dimethyl sulphides;

6. (6)

   ‘nitrogen oxides’ or ‘NO_x’ means nitric oxide and nitrogen dioxide, expressed as nitrogen dioxide;

7. (7)

   ‘non-methane volatile organic compounds’ or ‘NMVOC’ means all organic compounds other than methane, that are capable of producing photochemical oxidants by reaction with nitrogen oxides in the presence of sunlight;

8. (8)

   ‘fine particulate matter’ or ‘PM_2,5’ means particles with an aerodynamic diameter equal to or less than 2,5 micrometres (μm);

9. (9)

   ‘black carbon’ or ‘BC’ means carbonaceous particulate matter that absorbs light;

10. (10)

    ‘national emission reduction commitment’ means the Member States' obligation in the reduction of emissions of a substance; it specifies the emission reduction that as a minimum has to be delivered in the target calendar year, as a percentage of the total of emissions released during the base year (2005);

11. (11)

    ‘landing and take-off cycle’ means the cycle that includes taxi in and out, take-off, climb out, approach, landing and all other aircraft activities that take place below the altitude of 3 000 feet;

12. (12)

    ‘international maritime traffic’ means journeys at sea and in coastal waters by water-borne vessels of all flags, except fishing vessels, that depart from the territory of one country and arrive in the territory of another country;

13. (13)

    ‘pollution control zone’ means a sea area not exceeding 200 nautical miles from the baselines from which the breadth of the territorial sea is measured, established by a Member State for the prevention, reduction and control of pollution from vessels in accordance with applicable international rules and standards;

14. (14)

    ‘Union source-based air pollution control legislation’ means Union legislation which aims at reducing the emissions of air pollutants covered by this Directive by undertaking mitigation measures at the source.