s 21 Training and supervision of young persons working at dangerous machines.
(1) No young person shall work at any machine to which this section applies, unless he has been fully instructed as to the dangers arising in connection with the machine and the precautions to be observed, and— (a) has received a sufficient training in work at the machine; or (b) is under adequate supervision by a person who has a thorough knowledge and experience of the machine. (2) This section applies to such machines as may be prescribed by the Secretary of State, being machines which in his opinion are of such a dangerous character that young persons ought not to work at them unless the foregoing requirements are complied with.