I.-It is forbidden to assign young people to work involving the use or maintenance of :
1° Machines mentioned in article R. 4313-78, regardless of when they were first put into service ;
2° Machinery with moving parts involved in the performance of the work which cannot be made inaccessible during operation.
II -The prohibition mentioned in I may be waived under the conditions and in the forms laid down in section 3 of this chapter.