It very much depends on the country in which you are working.
Here in Ireland for example, there is no national standard, however, we would look to our neighbours in the UK for guidance. They currently refer to HBN 26 and HTM 03-01.
Hospital standards generally refer to Bacteria Carrying Particles per cubic metre and I am not aware of any references to non-viable counts as defined in ISO 14644-1.
Hope this helps.