An OECD report found 13 per cent of New Zealanders (20 per cent of men and 7 per cent of women) worked more than 50 hours a week compared with an average of 9 per cent for all other countries.
"Evidence suggests that long work hours may impair personal health, jeopardise safety and increase stress," the OECD report says.
Mr Finlayson's office referred questions on work hours to the Ministry of Business, Innovation and Employment, which reiterated the Government's policy that "employment legislation provides flexibility".
A ministry spokesman said work hours were regulated by health and safety provisions for employers to ensure workplaces were safe.
The spokesman said the Government had "set an ambitious target of at least a 25 per cent reduction in fatalities and serious harm injuries by 2020".
An independent taskforce reviewing workplace health and safety is due to report back to the Government in April 2013.
Opposition labour spokeswoman Darien Fenton said the Labour Party supported statutory working hours limits only for dangerous industries.
Ms Fenton said the "by agreement" clause of the 40-hour week under the Minimum Wage Act made it "effectively meaningless".
"Labour is concerned about weak regulation when it comes to health and safety and working hours," she said.
Truck drivers and forestry workers were two industries where Ms Fenton said "long and dangerous hours contribute to deaths and injuries".
"Labour's policy at the last election was to introduce industry bargaining where issues like working hours could be agreed across an industry or, if not agreed, arbitrated based on the standards in collective agreements already existing," she said.
"My view ... is that unless the Health and Safety Taskforce, which the Government has set up to look at our appalling health and safety record, comes to grips with the need for more, not fewer workers' rights ... all their good work will be wasted."
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Hours we work
13 per cent of New Zealanders work "very long hours", more than 50 per week
9 per cent is the OECD average of those who work more than 50 hours per week
20 per cent of New Zealand men work "very long hours"
7 per cent of New Zealand women work "very long hours"
1758 hours a year are worked by New Zealanders
1749 hours a year are worked on average by those in OECD countries
Source: OECD.org