translate English to French: The first sentence in the English version has to be replaced with: "It must be possible to ventilate each hold by means of two mutually independent extraction ventilators having a capacity of not less than five changes of air per hour based on the volume of the empty hold.  "
La première phrase de la version anglaise doit donc être remplacée par «It must be possible to ventilate each hold by means of two mutually independent extraction ventilators having a capacity of not less than five changes of air per hour based on the volume of the empty hold.».