21 CFR §1271.195

1. (a)Environmental control. Where environmental conditions could reasonably be expected to cause contamination or cross-contamination of HCT/Ps or equipment, or accidental exposure of HCT/Ps to communicable disease agents, you must adequately control environmental conditions and provide proper conditions for operations. Where appropriate, you must provide for the following control activities or systems:
   1. (1)Temperature and humidity controls;
   2. (2)Ventilation and air filtration;
   3. (3)Cleaning and disinfecting of rooms and equipment to ensure aseptic processing operations; and
   4. (4)Maintenance of equipment used to control conditions necessary for aseptic processing operations.
2. (b)Inspections. You must inspect each environmental control system periodically to verify that the system, including necessary equipment, is adequate and functioning properly. You must take appropriate corrective action as necessary.
3. (c)Environmental monitoring. You must monitor environmental conditions where environmental conditions could reasonably be expected to cause contamination or cross-contamination of HCT/Ps or equipment, or accidental exposure of HCT/Ps to communicable disease agents. Where appropriate, you must provide environmental monitoring for microorganisms.
4. (d)Records. You must document, and maintain records of, environmental control and monitoring activities.