inconceivable that any operation that requires the involvement of personnel will never result in the occasional infringement of microbiological action limits. At the very least there may be occasional laboratory or microbiological QA contamination. Corrective action such as retraining and disinfection is quite appropriate as long as it is effective and the problem does not persist. One of the responsibilities of microbiological QA is to help production, engineering and cleaning personnel to decide the most appropriate course in response to action limit infringements. Responses of action limit infringements applying to Grade C areas (nonaseptic areas) need be no more severe than this.
2. Infringements requiring preventive action to the process. When infringement of a particular action limit persists in a particular area, or where several independent action limits are breached, there is a strong likelihood of a systematic or persistent environmental problem that must be stopped. Such problems must be investigated. It may be necessary to close the facility while proper preventive action is implemented. Responses to infringements of action limits applying to change rooms ("white" change rooms) need not be more severe.
3. Infringements requiring action on product. Rarely is a sterile product rejected solely on the basis of infringements of microbiological environmental control limits. However, in relation to infringements applying to those limits in Grade A and Grade B areas, product rejection can never be totally discounted.
Information from the identity of the microorganisms isolated from Grades A and B areas may be as important as quantitative information. Action limits for these areas should include identification of all isolates. Most data from properly controlled areas of these classifications should follow the lines of 0 cfu. This recommendation should not present a significant workload. Satisfactory identification for these purposes is achievable by colonial morphology on agar and from Gram-staining. Therefore the information can be available on the same day as quantitative data.
An action limit should be set for isolation of "unusual microorganisms." This implies that there is some knowledge of the "usual" microorganisms. A responsible QA microbiologist will have a database of the usual types isolated in Grade A and Grade B areas, but all Gram-negative types should be seen as unusual enough in these areas to be perceived as an infringement of an action limit.
It is not always easy to find out what has gone wrong when an environmental action limit has been exceeded, and probably far more investigations are inconclusive than ever provide a definitive answer as to why the alert limit was infringed. Nonetheless, an infringement should be regarded as an opportunity to "test" the strengths of the sterility assurance system and to identify areas where improvement is merited. Production and engineering personnel must be involved. The identity of the microorganisms recovered can assist in focusing the investigation.
• Airborne types such as Bacillus spp., Micrococcus spp. and (to a certain extent) molds should initiate an investigation into the supply of filtered air and the maintenance of positive pressures versus less well-controlled areas. If building work is going on, attention may be given to how effectively it has been contained. The application of a sporicidal disinfectant, although recommended after all isolations of Bacillus spp. from Grade A and Grade B areas, may only deal with the symptom, and not the cause of the problem.
• Staphylococcus spp., Propionibacterium and some species of Micrococcus are usually indicative of personnel contamination. A review of past personnel monitoring data may be revealing. Frequently managers hesitate to discuss personnel monitoring data with operators unless limits are actually infringed. Sometimes an operator may be persistently giving "within-limits" counts as distinct from no recovery at all (which is the norm in Grade A and Grade B areas if hand disinfection and garment disciplines are being followed) and never be counseled until some other limit is infringed.
• Gram-negative bacteria (and to some extent molds) are water or dampness associated. Poor finishes, such as plastic-coated chipboard, can become soaked with disinfectant and yield Gram-negative recoveries.
Unfortunately every production operator knows of occasions where there have been environmental infringements when "everything went all right" and no environmental infringement when he knows there was a "screw-up." Often managerial interest in the investigative process may be sufficient to improve morale and add an edge to aseptic disciplines.
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