# Council Directive 2007/43/EC of 28 June 2007 laying down minimum rules for the protection of chickens kept for meat production (Text with EEA relevance), Division 3: The owner or keeper shall ensure that each house of a holding is equipped with ventilation and, if necessary, heating and cooling systems designed, constructed and operated in such a way that:

Extent: E+W+S+N.I.

(a) the concentration of ammonia (NH3) does not exceed 20 ppm and the concentration of carbon dioxide (CO2) does not exceed 3 000 ppm measured at the level of the chickens’ heads;
(b) the inside temperature, when the outside temperature measured in the shade exceeds 30 °C, does not exceed this outside temperature by more than 3 °C;
(c) the average relative humidity measured inside the house during 48 hours does not exceed 70 % when the outside temperature is below 10 °C.

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Source: https://www.legislation.gov.uk/eudr/2007/43/annex/II/division/2/division/3 (the official version)
Page: https://openlegislation.uk/eu-directive-2007-43/annex-II/division-2/division-3
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.