Ludo McFerran, manager of the national Safe at Home, Safe at Work program, will today address a Sydney conference on issues faced by women in male-dominated occupations and industries.

Ms McFerran said research from the University of Vermont had suggested that one in five perpetrators of domestic violence had caused or almost caused a workplace accident because of their preoccupation with their domestic relationship.

She said while the problem had not been quantified in Australia, there was a hidden cost of domestic violence for the employers of perpetrators who were often or suddenly absent from work and who inappropriately used workplace resources.

Some employees used their work email accounts and telephones to harass their victims.

"There is an effect on work performance and there is strong evidence they are causing accidents at work," Ms Ludo said.

Of concern, was the suggestion that some supervisors were inadvertently colluding with perpetrators by giving them time off work. Without realising, some supervisors were allowing employees to leave work to harass a partner or ex-partner.

She said employers could be more active in finding out whether their employees were the subject of a domestic violence order.

"Our message to supervisors is don't get sucked into this," Ms McFerran said. "They are not picking up on what is happening here.

"They need to start drawing a line at work about this behaviour.

"People get confused about what is happening in the personal life of employees and want to be supportive. But if it is having a negative impact on work, they need to talk to someone and get it sorted out. It has big implications for safety and productivity."

The latest Safe at Home, Safe at Work national survey found that a third of more than 3600 people surveyed had experienced domestic violence.

​Ms McFerran, who helps develop domestic leave clauses, said more than 550 Australian workplace agreements included such clauses.

"The majority are in the private sector and include big employees like banks, airlines, big retailers, universities and telcos," she said.

Unions NSW assistant secretary Emma Maiden said the women in male-dominated professions conference on Monday would address women who faced a range of issues including discrimination, bullying and harassment, isolation and intimidation.

"The conference provides a space for these women to network and share their experiences as well as discuss ways to break down the barriers that prevent more female participation in these occupations," Ms Maiden said.

"The aim is to equip them with the information and inspiration they need to return to their workplaces and represent, support and organise the other women they work with on a range of issues including workplace rights, pregnancy and discrimination, occupational health and safety, retirement savings and equal pay."

The conference comes a week after a United Nations Women report has found that women are still behind on pay, career and home help.

"The reality is women are working harder, for longer and for a lot less than their male counterparts," Ms Maiden said.

Moo Baulch, chief executive officer at Domestic Violence NSW Inc, said domestic violence is widely recognised as a workplace issue.

"Employers have a unique opportunity to respond compassionately to those impacted by violence and to prevent violence from occurring by taking a strong stance against violence through staff training and best practice policies," Ms Baulch said.

"Domestic violence often impacts on an employee's performance and workplace safety. We all have a responsibility to call out abusive relationships and particularly domestic violence wherever its happening - whether it's in the home, street or in the workplace.

"Employers have a vital role to play in challenging domestic abuse, by creating a workplace culture that challenges violence-supportive attitudes, by offering domestic violence leave provisions and taking a strong stance against perpetrators using the place of work or resources to perpetuate abuse."