Since 2002, at the end of each US Fiscal Year, CONCEPT HEIDELBERG elaborates the Warning Letter Report, a comprehensive analysis of warning letters issued during the previous twelve months. The data evaluation for 2006 is now closed so that the overall results will be published within the next two weeks. In advance, we have extracted interesting results in the field of maintenance and cleaning of equipment from the Warning Letter Report. They are as follows:

Maintenance and cleaning of equipment (211.67, Subpart D) is among the top 3 areas for which the US-American health authority FDA issued warning letters in 2006.

The most frequent deficiency that triggered warning letters in the field of equipment in 2006 was insufficient maintenance. Filters gave rise to complaints remarkably often, both in relation to cleanrooms and as regards water equipment. Some of the complaints related to the fact that HEPA filters were not clean, that filters were not changed within the prescribed frequency or that filter integrity tests were not conducted.

Other complaints referred to insufficient cleaning or non-compliance with the required cleaning procedures. The equipment in question were buildings, process, filling or packaging equipment.

Another frequent deviation in the technical field was the missing qualification of air handling systems for cleanrooms - first and foremost the lack of proof that no cross-contamination can take place over the HVAC system.