A decontaminating system (100) comprising a decontaminant reservoir (152), a transport fluid source (160) and a mist generating apparatus (10). The mist generating apparatus (10) has a longitudinal axis and comprises a first fluid passage (38) having a first fluid inlet (18) in fluid communication with the decontaminant reservoir (152) and a first fluid outlet (84), and a second fluid passage (90) having a second fluid inlet (20) in fluid communication with the transport fluid source (160) and a second fluid outlet (94). The first passage (38) surrounds the second fluid passage (90) and the first and second outlets (84, 94) are oriented relative to one another such that they have an angle of incidence between (5) and (30) degrees. The second fluid passage (90) includes a throat portion (92) located between the second fluid inlet (20) and the second fluid outlet (94), the throat portion (92) having a smaller cross sectional area than that of either the second fluid inlet (20) or second fluid outlet (94).