Workplace bullying is on the rise in New Zealand, with the country's largest health and safety association calling for employers to address the problem.

New Zealand has the second-worst rate of workplace bullying in the developed world, with one in five Kiwis affected by it.

The New Zealand Institute of Safety Management national manager Greg Dearsly said employers needed to be more aware of workplace bullying and the mental health and productivity impacts it has on employees.

"Workplace bullying is growing into a significant risk and is joining the many other issues health and safety professionals advise on every day," Dearsly said.


"Unfortunately, in many situations, the people involved are also managers, they often don't understand their behaviour is bullying and employees feel trapped, simply because they need the work and therefore stay silent."

Dearsly said there was not enough being done in New Zealand to address incidents of workplace bullying and harassment.

"Bullying is a social issue that needs addressing - it shouldn't be taken lightly as injury or illness caused by a person's behaviour in the workplace, it is characterised as a hazard under the Health and Safety at Work Act," he said.

"There isn't enough being done in New Zealand to properly address incidents of workplace bullying and harassment. There needs to be a more structured approach to help people in unsupportive work environments."

Research from the Harvard Business Review suggests 60 to 80 per cent of workplace bullying incidents are caused by stress.

Workplace happiness leads to a 12 per cent spike in productivity, according to an economic study by the University of Warwick.

"A job is such an important part of life and no one goes to work to be treated badly. But the evidence shows it's becoming a larger problem," Dearsly said.

"Our members are seeing more of it all the time, with managing the effects of mental health becoming a bigger part of their everyday work."