This test protocol is supplementary to Quality Assurance of Aseptic Preparation
Services, Fifth edition, Edited by Alison M Beaney, Pharmaceutical Press, 2016.

The purpose of HEPA filters in cleanrooms, controlled environments, workstations and
cabinets is to control particles and microbes so that environmental standards can be
maintained and the particulate and microbiological challenge to processing is minimised.
HEPA filters may also be used to provide operator protection in safety cabinets.