Field test of pharmaceutical cleanroom cleanliness subject to multiple disturbance factors

Abstract

Biopharmaceutical cleanrooms have high cleanliness requirements to supervise and manage processes and ensure the quality of production. However, on-site data, including real-time particle concentrations and differential pressure in biopharmaceutical cleanrooms, are scarce for both operational and at-rest conditions. In this study, a field experimental investigation of multiple disturbance factors in a cleanroom environment was performed in a newly built cleanroom. The impact of the number of personnel, entry of personnel, and air change rate on the cleanliness level was measured and analyzed. It was concluded that: (1) a notable over-specification of cleanliness was observed in the operational state. The particle concentrations with size larger than 0.5 μm were 1041 pc/m3 and 2901 pc/m3 in the temporary storage room and configuration room, respectively, which was considerably lower than the required Class B specification; (2) An increase in the number of people entering the room and extension of the door opening time may cause the invasion of more particles to the cleanroom with higher cleanliness. The particle concentrations increased by approximately 2000 pc/m3 with the addition of one person. (3) In the at-rest state, the particle concentration was two orders of magnitude lower than the standards. Therefore, the supply air volume in the at-rest state can be reduced when other disturbance factors are under control. The active power of the supply air fan was reduced by 41.7% in this stage, indicating great potential for energy saving. The field measurement provides evidence of the effect of disturbance factors on the cleanliness.