12. Scaffolding may be assembled, dismantled or significantly altered only under the supervision of a competent person and by persons who have received appropriate and specific training in the operations envisaged which addresses specific risks which the operations may entail and precautions to be taken, and more particularly in—
(a)understanding of the plan for the assembly, dismantling or alteration of the scaffolding concerned;
(b)safety during the assembly, dismantling or alteration of the scaffolding concerned;
(c)measures to prevent the risk of persons, materials or objects falling;
(d)safety measures in the event of changing weather conditions which could adversely affect the safety of the scaffolding concerned;
(e)permissible loadings;
(f)any other risks which the assembly, dismantling or alteration of the scaffolding may entail.