Performance Evaluation of Cleanrooms Against Biocontamination

An evaluation system of bio-contamination control shall be established, implemented and maintained within cleanrooms, especially biological cleanrooms. Generally, these this evaluation is performed with control of particulate matter, e.g. DEHS (di-ethyl-hexyl-sebacate), DOP (di-octyl-phthalate), PSL (Poly-Styrol Latex), to predict the bio-contamination control effect of cleanrooms. However, no data have been available to evaluate systematically bioaerosol characteristics in relationship to particle counts in different classes of cleanrooms. In addition, although the filtration of airborne particulates has been studied extensively, the filtration of airborne microorganisms has not been specifically addressed by theory and has seen limited empirical study. Thus, particle counting should, of course, not take the place of microorganism measurements. A evaluation system of bio-contamination control within cleanrooms is given, and then challenged with a model cleanroom laboratory. Results show that performance evaluation of bio-contamination control within cleanrooms should be conducted with bioaerosol, which can directly reflect bio-contamination control ability of cleanrooms, instead of particulate matter aerosol. Case study results indicate that air distribution with ceiling supply and downside exhaust air distribution mode has better bio-contamination control ability than that with ceiling supply and exhaust air distribution in cleanrooms.