What is the maximum number of hours a young worker under the age of 18 may work?

Young workers under the age of 18 must not be permitted to work for more than 40 hours in any week or for more than eight hours on any day (including overtime hours). In addition they must not be employed at night between 10 pm and 6 am or, where their contract requires them to work after 10pm, between 11 pm and 7 am.