Occupational Radiation Dose units - (yearly limits) as given by ICRP are
5 mSv per year and 10 mSV in 5 yr period (cumulative)
50 mSv per year and 100 mSv in 5 yr period (cumulative)
500 mSv per year and 2500 mSv in 5 yr (cumulative)
5000 mSv per year and 5 Sv in 5 yr (cumulative)