The paper also urges governments to cap the working week, including overtime, at 38 hours, to help avoid accidents caused by sleep deprivation.

University of South Australia psychologists Natalie Skinner and Jill Dorian surveyed about 970 workers and self-employed business people about their work and sleep habits, moods, and access to leave.

About 30 per cent often felt fatigued, saying they were ''extremely tired'' or ''completely exhausted''.

A similar proportion never or rarely had seven hours of sleep a night, however, this rose to 40 per cent among parents of dependent children.

Fathers were more likely to report a lack of sleep than mothers, though women were more likely to be fatigued.

Past research has shown that either lack of sleep or disrupted sleep patterns can significantly increase the risk of workplace and road accidents.

Inadequate sleep has also been linked with heart disease, cancer and obesity, as well as mental illness and poor decision-making.

The paper's authors say Australians' work and sleep habits ''are likely to place significant strain on workers' capacity to be effective and engaged workers, parents, partners, friends and community members''.

''The workers in this study concurred, identifying many personal and work outcomes that were compromised as a result of their fatigue.''

The pair also expressed concern at the lack of research on the effects of non-paid work and fatigue.

''Caring responsibilities, for example, can create the 'double burden' of work and family demands that is likely to increase the risk of fatigue from long hours or intensive work.''

Australia's national employment standards set 38 hours as a maximum length for the working week, though exceptions are allowed for ''reasonable'' requests to work longer.

However, the paper says this exception is applied too often.

The authors say: ''Our findings suggest that working 45-plus hours significantly increases the risk of negative outcomes for fatigue and sleep deprivation.

''These outcomes, in turn, are associated with reduced productivity, community and workplace safety. Therefore, it is recommended that an upper limit be set for 'reasonable' hours no longer than 38 weekly hours, even taking into account operational needs of the workplace/enterprise.''

Workers in every developed nation except France have gradually reduced the number of hours they work over the past decade.

In 2010, the average ''usual weekly hours'' an Australian employee worked on their main job was 36, compared with 30.6 hours in the Netherlands and 49.3 in Turkey.

Last year, the New Economic Foundation, a leftist research group, urged governments to legislate a 21-hour working week.