Extended hours of work

Extended work hours can affect the amount of time available for adequate sleep opportunity. It is important to monitor the amount of hours workers are doing each day.

You can ensure workers aren’t required to work unnecessary extended hours by:

  • ensuring sufficient cover for workers who are on annual or sick leave
  • if overtime is necessary, plan for it so workers can schedule their activities around it

Where considering overtime:

  • Limit overtime to four hours for eight hour shifts.
  • Limit overtime to two hours for shifts longer than 10 hours.
  • Do not allow overtime for shifts longer than 12 hours.
  • Limit total hours per week to 55.
  • Have a policy on second jobs – ensure that the worker understands the obligation to get sufficient sleep and to be fit for duty.


Shift work can be a contributing factor in work-related fatigue. Ensure the roster provides for a continuous seven to eight hours sleep in each 24 hours, and at least 50 hours sleep for every seven days.

If on a rotating three shift roster system, forward rotation (day, afternoon to night shifts) is tolerated better.

When determining your work schedules:

  • limit number of consecutive night shifts to four to minimise accident risk.
  • end night shifts by 8am.
  • ensure there is a minimum of 12 hours between consecutive shifts.
  • ensure that roster allows for at least two full nights sleep after the last night shift.
  • allow short naps of no longer than 15–20 minutes if it fits in with the type of work that is being done.
  • consider whether 12 hour night shifts are really necessary.
  • use additional control measures, such as two hourly breaks of at least five to ten minutes duration.
  • have a room for workers to sleep before commuting home.
  • encourage healthy eating at work and provide access to healthy food options at work to minimise health risks.

Time of day

Minimise early morning starts before 6am as workers have less time to get adequate sleep – it is very difficult to go to sleep during the early evening (6–9pm) as our body clocks are set to alertness at that time.

  • Avoid more than five consecutive early morning starts.
  • Encourage carpooling or provide transport.

Roster and work design

Consider the following:

  • increasing supervision
  • allow regular breaks
  • length of shifts – depends on physical and mental load of the work
  • distribution of leisure time – allow for adequate rest and recovery
  • regularity of shift system – allows workers to prepare for work
  • previous hours and days worked – the effects of fatigue are cumulative, workers may have sleep debt due to the length of previous shifts. Giving workers two successive full days off within a seven day period allows them to catch up on their night sleep
  • type of work being performed – pay particular attention to the level of physical and/or mental effort required
  • time of the day when the work is being performed – avoid safety critical tasks during the early hours of the morning (3-5am).

Frm: worksafe.qld.gov.au