With regards to staff, there is the obvious confidentiality issue with the possible presence of patient records so I perform a CRB check and am happy to submit to additional confidentiality stipulations (within sensible reason of course).
The only other consideration with staff is that it may be 'recommended' that they had Hep B vaccination, advisory but not essential.
I am, of course, assuming that clinical waste is not part of your responsibilities in this case.
