Managing Shiftworkers' OHS: the role of employment contracts

By Philippa Gander, Lana Le Quesne, Hazel Armstrong and Anne-Marie Feyer

An examination of how the special OHS challenges of shiftwork were addressed in 100 collective employment contracts in the New Zealand metal manufacturing sector in 1999 (before the repeal of the Employment Contracts Act of 1991).

The study focused on work timing, duration and predictability, sleep recovery opportunities, and sick leave and annual leave provisions.

The usual strategy for managing the work/recovery balance was through penalty pay rates for overtime, delayed minimum rest, and callback. Most contracts did not specify minimum notification of roster changes. None addressed the added difficulty of obtaining recovery sleep at unusual times. Minimum daily rest periods were often insufficient to ensure recovery sleep.

The authors conclude that, although there is scientific evidence for the following shiftwork management principles:

• Adequate sleep is essential for maintaining waking function, both at work and in other life activities

• Work which displaces the timing of sleep will usually cause sleep loss, the effects of which accumulate

• The sleep debt must be paid off regularly, with at least two nights of undisturbed sleep

• The reduced functional capacity of people at night and in mid-afternoon in some cases) must be taken into account because it effectively reduces the safety margin in any operation

There is a failure to communicate these from the scientific community to workplaces. New Zealand government departments have addressed the issues in piecemeal fashion.

(Journal of Occupational Health and Safety - Australia and New Zealand; vol. 21 no 2, April 2005; pp121-8)