The mesh bags, called "spit hoods", are a response to the 4 percent of assaults on prison guards involving spitting, The Press reported.
Guards will soon be authorised to put bags over inmates' heads to prevent them spitting and spreading disease .
Corrections Prison Service assistant general manager Brendan Anstiss said a legislative change to add spit hoods to standard prison equipment was expected by Christmas, he said.
The bags would not be a standard practice and would be used only on prisoners identified as spitters, Mr Anstiss said.
Corrections was introducing a range of protective gear for prison guards including the bags, an "operations trial" of pepper spray, stab-proof vests and batons.
