40. Residual hazardous materials shall be stored in vessels, except in the case of
(1) contaminated empty vessels referred to in paragraph 3 of section 4;
(2) gas cylinders referred to in paragraph 4 of section 4;
(3) solid materials at 20 ºC placed in bulk inside a building in an area laid out to receive such materials;
(4) solid materials at 20 ºC referred to in section 32 or other solid materials at 20 °C whose heap storage area complies with the standards prescribed by sections 72 to 76;
(5) contaminated objects that, because of their size, cannot be placed in a receptacle or cargo container. In such a case, those objects shall be placed in a building, under a shelter or outside in an impermeable basin that is compatible with the deposited objects and that shall be covered with an impermeable canvas whose extremities are attached to the edges of the basin.