www.Droit-Afrique.com This hydraulic back pressure valve shall be frequently cleaned and extensively washed at least once every day. Sinks shall be built using impervious and properlyjoined materials. They shall slope in the direction of the discharge pipe and shall be built such that they do not release any odour. Works in wells, pipes, sewage pits, tanks or any apparatus whatsoever that can contain poisonous gas shall be carried out only after the air would have been decontaminated through effective ventilation. Art.D.170-4.- Dust and discomfort-causing, unhealthy or toxic gases shall be directly discharged outside the work premises as they are being produced progressively. An effective device to eliminate dust shall be installed to deal with dust caused by grinding wheels, grinders, threshing machines and all other mechanical equipment. Downward ventilation shall be used to deal with heavy gases, such as mercury and disulphide vapours. Tables or working equipment shall be directly connected to the fan. Spraying irritating or toxic materials or performing other operations such as shifting or packaging these materials shall be done mechanically in closed equipment. In exceptional cases where the competent labour inspector admits that it would be impossible to discharge, through protective measures, the dust, vapours or irritating or toxic gases, prescribed herein above, masks and appropriate protective devices shall have to be made available to workers. The company head shall have to take all the necessary measures so that these masks and devices are kept in a good state of operation and disinfected before they are given to a new holder. Art.D.170-5.- In closed premises kept set aside for work, the cubic foot per minute per person employed may not be lower than 7 cubic metres. The cubic foot per minute shall be ten metres at least per person employed in laboratories, kitchens, and cellars. The same shall apply to stores, shops and offices open to the public. Implementing Decree of the Labour Code Mali Art.D.170-6.- Closed premises meant for work shall be aerated. They shall have windows or any other opening with a moveable frame leading directly to the exterior and ensuring sufficient aeration to prevent an excessive temperature increase. In premises located underground, measures shall be taken to introduce fresh new at a rate of 30 cubic metres at least per hour and per person employed and so that the volume of air introduced as such is not in any event lower per hour to two times the volume of the premises. These measures shall be such that the air introduced underground is, where necessary, purified beforehand through filtration or any other effective method. The used and polluted air shall not be discharged through passages and staircases. To implement these provisions, a premises located underground shall refer to any premises whose floor is found at a level lower than that of the surrounding ground when it does not have a window or any openings with moveable frames leading directly to the exterior and making it possible to renew the air in sufficient quantity and to keep it in a state of cleanliness necessary to ensure the health of the personnel. Art.D.170-7.- During interruptions in work, the air in the premises shall be totally renewed. Art.D.170-8.- Closed premises used for work, their appurtenances and notably passages and staircases shall have lighting. The lighting shall be sufficient to ensure work and movement safety. Art.D.170-9.-Workers and employees shall be prohibited from taking their meals in premises meant for work. Art.D.170-10.- Measures shall be taken by the head of the institution so that workers have good quality water in sufficient quantity for drinking. Should this water not come from public distribution, which does not guarantee its potability, the labour inspector may notify the employer that it has to ensure that the water is analysed at its expense. 16/29