Prison staff are not allowed to wear protective vests whenever they want to, according to the Department of Corrections' chief executive.
Barry Matthews is retiring at the end of this year and appeared for his final financial review of the department before Parliament's Law and Order select committee on Wednesday.
Mr Matthews says in the past year - which included the fatal attack on prison officer Jason Palmer in May - nearly 3500 prison officers have done advanced safety training.
The training includes techniques to de-escalate threatening situations and the use of equipment such as protective vests in volatile situations.
But Mr Matthews says staff who want to wear vests all the time are not allowed to.
He says wearing that equipment can "heighten the aspect of confrontation ... which works against de-esclating the climate within a prison."