Two prison guards were taken to hospital after being stabbed with a pen and a third was doused with hot coffee during an attack at Casuarina jail which has renewed pressure for a purpose-built unit for prisoners with mental health issues.
WA Prison Officers Union secretary John Welch said one officer was lucky not to lose an eye during the incident at the men's jail on Saturday.
Mr Welch said the officer had been stabbed in the face with the pen, causing a 3cm-long gash under his eye. A second had been stabbed in the torso and a third had hot coffee poured on him.
The stabbed officers were taken to hospital and released on the same day but had been unable to return to work.
Mr Welch said the prisoner involved had been assessed as having serious mental health issues and had previously been treated at the maximum-security Frankland centre at Graylands Hospital.
Mr Welch said prison staff had been told the Frankland centre was short of beds and capacity at Graylands was under more pressure because of the closure of another unit at the hospital.
"Our members are not trained or equipped to deal with these people and this incident is an example of what can happen when they have to manage prisoners who have serious mental health issues," he said.
"The previous government promised to establish a purpose-built forensic unit to house mentally ill prisoners. Clearly this hasn't happened and we want the current Government to commit to this plan."
A spokeswoman for the State Forensic Mental Health Service said the former patient understood to be involved in the assault was discharged in a mentally stable state in February and not because of any bed capacity issues.
The prisoner had been referred back to the service and was being accommodated within the statutory timeframe of one week.
The Mental Health Commission said services in prison and secure beds would be examined as part of a 10-year plan for mental health services.