“Factors to consider in selecting sites for routine surveillance are: 1. At which sites would microbial contamination most likely have an adverse effect on product quality? 2. What sites would most likely demonstrate heaviest microbial proliferation during actual production? 3. Should site selection involve a statistical design (e.g., following the calculations in Federal Stan- dard 209E) or should site selection be made on the basis of grid profiling? Should some sites for routine monitoring be rotated? [Note from author: As 209e has been withdrawn in favor of ISO 14644, the answer is “No”] 4. What sites would represent the most inacces- sible or difficult areas to clean, sanitize, or disinfect? 5. What activities in the area contribute to the spread of contamination? 6. W ould the act of sampling at a given site disturb the environment sufficiently to cause erroneous data to be collected or contaminate product?”