French to English Medical Medical: Pharmaceuticals Inpection of Pharma establishment

Yet another acronym from pharma inspection report. This appears under "quality management" and refers to a deviation dossier " cv des aires témoins encadrant NCF" it then mentions a specific drug. I think NCF = non-conforme, so it is suggesting I think that the "cv" samples? taken from the area in which the drug is produced are non-compliant. The only relevant acronym I can find is "charge virale" but I think this is only applied to blood samples?