Many prison officers in Northern Ireland took more than three weeks off sick last year, it has been revealed.
Injuries or fractures were the main reason for average absences of 17 days, significantly higher than the civil service standard, the official research body for the Stormont Executive said. One in five uniformed staff endured one or more spells of long-term leave because of poor health.
Warders have been dealing with a no-wash protest from dissident republicans amid escalating tensions over strip searching. Prison officer David Black was shot dead by the IRA this month.
Prison Officers' Association (POA) chairman Finlay Spratt said: "It is a very difficult and dangerous job and many prison officers are assaulted."
He said staff wore batons while doing their rounds but had to use minimum force. "It is the nature of the job that you do not know when a prisoner is going to react, it could happen in a second," Mr Spratt added.
"We are dealing with people that can be very violent and you do not know when it is going to happen. This demonstrates the volatility of the job that we do."
He accused the authorities of destroying morale within Northern Ireland's prisons following the shock departure of former director general Colin McConnell this year.
Mr Spratt also lambasted the authorities in England, claiming some prisoners there were locked up for 23 hours a day. "Who are they to teach us anything?" he asked.
Earlier this week Justice Minister David Ford said the sickness level across the prison service was running to around 14 days. A comparable figure for England and Wales was just under 10.
According to the statistics report, when absence is broken down to uniformed prison officers in Northern Ireland, the total is 17 days on average. Because of this, Mr Ford's department has the highest level of absence in the Stormont administration. The Northern Ireland Statistics and Research Agency report - Sickness Absence in the Northern Ireland Civil Service (NICS) 2011/2012 - said public servants took 10.1 days off sick on average last year, just missing their target.