WorkSafe Executive Director Health and Safety Narelle Beer urged employers to mark World Mental Health Day by making sure they have policies, processes and training in place to address risks such as bullying, aggression, trauma, fatigue, stress and high job demands.
Of the 28,682 claims received by WorkSafe in the 2021-22 financial year, 4340 were for mental injury.
While claims for work-related mental injuries now make up 15.1 per cent of all new claims, up from 13.1 per cent the previous year, they are on track to grow to a third of all WorkSafe claims by the end of the decade.
Dr Beer said mental injuries often needed more recovery time than physical injuries, meaning more time off and higher costs.
"Sadly, while three quarters of workers with a physical injury are back on the job in six months, just 40 per cent of workers with mental injury return to work within that time," Dr Beer said.
"Just because a mental injury is harder to see, doesn't mean it can't be prevented."
"We're putting employers on notice that they have a legal obligation to make sure their workplaces are psychologically safe."
Dr Beer said employers who fail to take reasonable steps to prevent mental injury can face prosecution under the Occupational Health and Safety Act, including potential fines of up to $332,000 for an individual or $1.66 million for a body corporate.
"Our message to employers is clear, if you turn a blind eye to bullying, harassment, or other psychological health hazards then you're risking your workers' safety, lost productivity and potential hefty fines," Dr Beer said.
Throughout October, WorkSafe will use social media to remind employers of the need to address psychological health hazards at work.
WorkSafe provides support and guidance to Victorian employers to reduce workplace mental injury risks through the WorkWell program, which has engaged with more than 13,200 workplaces since its 2017 launch, through grants, learning networks and resources.
The WorkWell Toolkit for Small Business, launched earlier this year, provides free tools and information such as case studies, policy templates, videos and tip sheets from trusted organisations such as Beyond Blue and RUOK.
On 26 October WorkSafe is offering a free webinar on managing psychosocial hazards in the workplace as part of Health and Safety Month.