29.—(1) No person may stun pigs by exposure to gas unless each pig is exposed to the gas for long enough to ensure it is killed.
(2) The business operator and any person engaged in the stunning of pigs by exposure to gas must ensure that—
(a)the gas stunner, including any equipment used for conveying a pig through the gas mixture, is designed, constructed and maintained so as to—
(i)avoid compression of the chest of a pig;
(ii)enable a pig to remain upright until it loses consciousness; and
(iii)enable a pig to see other pigs as it is conveyed in the gas stunner;
(b)adequate lighting is provided in the gas stunner and the conveying mechanism to allow pigs to see other pigs or their surroundings;
(c)the gas stunner is equipped to maintain the gas concentration, as appropriate, in the gas stunner (in accordance with Table 3 of Chapter I of Annex I);
(d)there is a means of visually monitoring pigs which are in the gas stunner;
(e)there is a means of flushing the gas stunner with atmospheric air with the minimum of delay;
(f)there is a means of access to any pig with the minimum of delay; and
(g)no pig is passed through or allowed to remain in the gas stunner at any time when the visible and audible warning signals have been activated or when there is any defect in the operation of the gas stunner.
(3) The business operator and any person engaged in the stunning of pigs by direct exposure to gas mixture 1 (“carbon dioxide at high concentration”) in Table 3 of Chapter I of Annex I must ensure that—
(a)no pig enters the gas stunner if the displayed concentration by volume of carbon dioxide in the gas mixture falls below 80%; and
(b)once a pig enters the gas stunner it is conveyed to the point in the gas stunner of maximum concentration of the gas mixture within a maximum period of 30 seconds.