We routinely monitor our non-sterile manufacturing facility air by active air sampling. Due to the air sampler broke down, we had to use alternative method of passive air sampling (Settle plate). This was done as emergency change control. My question is how can I derive limits for this emergency change control for settle plate method?
Not required derive limit. Generally the guidelines are like USP/BP/IP/EP/JP is says to class 1,00,000 the limit was 100 CFU/plate and class 10,000 limit was 50 CFU/plate. So the limit was not only emergency cases its usually followed to many concerns.