What is a reasonable target for a zone 3 swab at preop?

What is a reasonable target for a zone 3 swab at preop ?   We are looking at <100 cfu sq in for Zones 1 and 2 but not sure if this is a reasonable specification for Zone 3.  Can I get some input ? 

They just recently expanded to include Zone 3 - so I have no history.   I also need to know any reference material that I might use as justification to expand this target number.

Thank you for any direction you can give me !

What organism are you testing for - the limits would be very different depending on whether you were looking at APC or yeasts or ents.

S

<100 cfu sq in for Zones 1 and 2 for which target species?

for us, Zone 1 and Zone 2 has limit <10 cfu/ area or per gram of dust on EB monitory. for Zone 3, there is not limit, only monitory target <100 cfu/ area or per gram of dust on EB monitory