danger from uv light in BSC?

[Deborah Hailstones]

     Dear all,
     
     I'm very interested to hear other peoples' thoughts and experiences 
     about occupational health and safety issues associated with using the 
     uv light in a BSC.
     
     I have a colleague who is getting increasingly heated about the use of 
     the uv light (5-10 minutes) before using a BSC to add template to 
     diagnostic PCR.  I like to do this to cross link (ie attempt to 
     'remove') any exogenous template which may be present, since the 
     cabinet is used by many people for many things, including the 
     inoculation of microorganisms.  I like to think that this procedure 
     reduces the chance of cross-contaminating my reactions (though I 
     realise opinions obviously differ on this).  
     
     My colleague, however, is convinced that this presents a serious 
     hazard in terms of a) uv radiation (not my use of the word) leaking 
     from within the cabinet (which is sealed using the shield provided) 
     and b) the action of the light on the air inside, which is producing 
     free radicals "including ozone". 
     
     I agree that direct exposure to excess uv is a concern (and that 
     nobody should enter the cabinet whilst the uv is turned on! ;-) ), but 
     does anyone out there have any evidence/opinion on this matter?  I'm 
     all for OH&S, so I'm interested to see what the general feeling is.   
     
     I know that this type of question often leads to many spinoffs, so can 
     reiterate that I am asking *specifically* about the effects/dangers of 
     uv light, in a covered BSC, on other workers in the room whilst the 
     light is on and then when the shield is removed and the BSC turned on.
     
     Thanks in advance for any contribution,
     
     Deb