PT  - JOURNAL ARTICLE
AU  - Masayuki Ogawa
TI  - Contamination Control in HVAC Systems for Aseptic Processing Area PART I: Case Study of the Airflow Velocity in a Unidirectional Airflow Workstation with Computational Fluid Dynamics
DP  - 2000 Jan 01
TA  - PDA Journal of Pharmaceutical Science and Technology
PG  - 27--31
VI  - 54
IP  - 1
4099  - http://journal.pda.org/content/54/1/27.short
4100  - http://journal.pda.org/content/54/1/27.full
SO  - PDA J Pharm Sci Technol2000 Jan 01; 54
AB  - A unidirectional airflow workstation for processing a sterile pharmaceutical product is required to be “Grade A,” according to EU-GMP and WHO-GMP. These regulations have employed the wording of “laminar airflow” for unidirectional airflow, with an unclear definition given. This seems to have allowed many reports to describe discussion of airflow velocity only. The guidance values as to the velocity are expressed in various words of 90 ft/min, 0.45 m/sec, 0.3 m/sec, ± 20%, or “homogenous air speed.” It has been also little clarified how variation in airflow velocity gives influences on contamination control of a workstation working with varying key characteristics, such as ceiling height, internal heat load, internal particle generation, etc. The present author has revealed following points from a case study using Computational Fluid Dynamics: the airflow characteristic in Grade A area shows no significant changes with varying the velocity of supplied airflow, and the particles generated from the operator will be exhausted outside Grade A area without contamination.