50 Years, 50 Articles

Title Authors Abstract
A Newly Developed Clean Hood for Isolation of Patients Thought to have Airborne Infectious Disease

Hidekazu Nishimura, Fumie Kitamura, Soichiro Sakata, Yasushi Kamimura A new medical clean hood was developed for isolation of patients thought to have airborne diseases, such as pandemic influenza and the like. The hood is intended to be used in a ward where many patients are
treated simultaneously in the same closed airspace such as a dialysis facility, in order to prevent cross infection of other patients by the potentially infected patient. The hood consists of foldaway framework, a
fan High Efficiency Particulate Air Filter (HEPA) unit, and transparent polypropylene curtains. The patient is treated inside the hood, and airborne microbes from coughing or sneezing by the patient are contained
inside the hood, and the air containing microbes finally passes through the fan HEPA unit to be released outside the hood as clean air.
Clean HoodIsolationIsolation RoomInfectiousDiseaseAirborne
Airborne Biological Contamination: Monitoring and Control

Vance Bergeron Airborne Biological Contamination includes a vast range of particulate and molecular species that present specific challenges for monitoring and control. In particular, the notion of viability places restrictions on
sample collection and analysis. Furthermore, controlling airborne levels of microorganisms requires technologies capable of inactivating and/or chemically eradicating them, as simple capture onto filter media
can lead to proliferation and subsequent release. The advent of new assay capabilities using rapid microbiological methods in combination with effective air sampling techniques holds promise for future
online monitoring systems, while combinations of different technological bricks can be used to tailor air-treatment systems to remove, inactivate and chemically transform particulate, biological, and molecular
airborne contamination.
AirborneContaminationBiological ContaminationMonitoringControl
Cleaning And Disinfection Program Part Of The Lifecycle Approach: A Risk Based Rather Arbitrarily Imposed Approach

Walid El Azab Is the rotation of more than one disinfectant along with a sporicidal agent mandatory for cGMP compliance? The article will present and analyze the regulatory requirements related to contamination control programs then dive into the requirements for cleaning and disinfection programs, including disinfectant rotation along with a sporicidal agent. the article discusses the process of selection and number of disinfecting agents to be used, the frequency of application, and rotation of (one or more) disinfectants along with a sporicidal agent. Finally, the article reaffirms the importance of periodically reviewing microbial data and auditing practices to confirm the effectiveness of the cleaning and disinfection program including the disinfectant rotation and frequency choice.
CleaningDisinfectionLifecycle ApproachCgmpRisk Based ApproachMicrobiology
Influence of External Biological Contamination on Particulate Behavior

Michel Thibaudonab, Julien Clertantc Seasonal Biocontamination is frequently observed both inside cleanrooms and in/on the product. When carrying out sampling of the cleanroom environment, it is necessary to also
sample the outside environment. High levels of pollen and fungal spores outdoors in summer and autumn can correlate to detection of such contaminants inside the clean airlock and
even inside the cleanroom, if appropriate non-cultural methods of detection are used for their detection, whereas classic culture methods are ineffective. Monitoring on a daily or weekly
basis with appropriate method, it is easy to correlate outside levels of pollen and fungal spores with impact inside the installation, and identify the principal mode of transmission as
the personnel, the devices, etc. This enables optimization of gowning and cleanroom cleaning practices to maintain effective control in response to the challenge.
CleanroomContaminationOutdoorIndoorCoriolis
Real Time Microbial Detection by Laser Induced Spectroscopy and Its Application in Contamination Control

J.P.Jiang A technology based on optical spectroscopy has been developed for real time detection of environmental microbes and continuous monitoring of the environment. This technology utilizes
Mie scattering for airborne particle size measurement in the range of bacterial matters, and the detection of intrinsic UV-induced fluorescence from certain bio-chemicals inside bacterial cells
as a biological marker. The optical instrumentation techniques used to achieve the requisite detection sensitivity and the procedure for its validation test will be presented.
One necessary aspect for applying this technology in contamination control is how to correlate its results to compendial microbiological methods and how to set the new limits based on this new
method. A statistical process control (SPC) approach to the environmental monitoring of bioburden in parenteral aseptic facility is proposed to achieve this goal. This presentation will
cover (1) the procedure of setting new limits using a new instrument, (2) the control chart methodology of utilizing environmental monitoring data to assess the state of control in a
parenteral production environment and to troubleshoot the root cause when a variation from normal trend is detected.

Some application examples will be used to illustrate how to utilize the real time microbial detection features of this technology in the environmental monitoring and contamination control.
Topics of discussion include sensor placement, data analysis, graphic data display, and trend analysis.
Real Time Microbial DetectionEnvironmental MonitoringTrend Analysis
Zero "0" Contamination Cleanrooms

Dr, Horst Weissieker From various points of views zero contamination cleanrooms will be necessary in the next 5 years latest. Not only for the coming semiconductor production environments, but also for the nanotechnology and
biotechnology as well as bio-safety new requirements have to be defined. This affects not only cleanroom and clean air but also all other aspects of contamination control from ultrapure media to ultrapure surfaces to the measurements and monitoring of the contaminants and last but not least the control of the contaminations.
CleanroomContaminationZero ContaminationVdi2083-6Iso14644-7
Performance Required for Air Shower and Effectiveness of Performance

Akihiro Maruyama, Mamoru Okamoto, Toru Kawamata, Han Hyuck Hee Before entering into cleanroom, people will use Air Shower to clean up the body covered by clean garments. Air Shower is expected to protect cleanroom environment from particle and keep the room pressures. Bu it is saying once in a while, that Air Shower is contaminate cleanroom . We evaluated the expected performances and effectiveness of Air Shower, that was installed between test cleanroom and the owning room as simulation.
Air ShowerCleanroomContamiantion
Nitrogen Purging of Front-opening Unified Pod (FOUP) for 450mm Wafer Manufacturing

Chun-Yong Khoo, Chen-Wei Ku, Shih-Cheng Hu This study aimed to investigate the nitrogen purging of front-opening unified pod (FOUP) with nitrogen for 450 mm wafer which involves stringent cleanliness requirement of water vapor content (RH ≤ 3%)
within the container, besides airborne molecular contamination (AMC). A parametric study was conducted with factors considered to affect the extraction of water vapor content includes the
configuration of plenum injector, purging outlet and FOUP. Computational fluid dynamic (CFD) was employed and Langmuir adsorption models were used to construct physical models of contaminant
concentrations in the FOUP. The results showed that the configuration with nitrogen entering from the rear inlets and the front vent holes and porous ceramics plenum demonstrate favourable water vapor
depletion rate within the gaps formed between the wafers in a fully loaded FOUP. Elaboration of nonlinear fitting was applied to theoretical model and experimental data yields the desorption coefficient
Kd as 0.4 kg/s.
Nitrogen PurgeWaferFoupWafer Manufacturing Airborne Molecular Contamination
A short Introduction to Cleanliness Technology: Meeting the future Challenges

Udo Gommel, Guido Kreck For semiconductor components, the demand to improve performance and velocity as well as energy consumption is met through miniaturization. The continuing trend to miniaturize semiconductor structures can be observed since several decades and requires, among other things, sophisticated cleanliness technology. Cleanliness technology in this context is to be understood as the chain of all activities taken to control and reduce all contamination harmful to the product. Because of the very challenging particulate and outgassing contamination levels, semiconductor industry still claims technological and economic leadership in terms of cleanliness technology. But no longer only semiconductor industry is relying on cleanliness technology as the following case studies graphically demonstrate:
In life science industries, mainly microbiological contamination is controlled to prevent users and patients from severe health issues caused by poor hygiene or cleanliness of the highly effective pharmaceuticals or very innovative medical devices.
Space exploration combines nowadays the challenging cleanliness requirements of semiconductor and pharmaceutical industry to be in compliance with the planetary protection program, the guiding principle to preserve planetary and terrestrial conditions for future generations.
And even automotive industry discovered the benefit of cleanliness technology almost ten years ago: Metallic micro sized particles (>50μm) were identified as critical contamination because they can cause malfunctions in fluidic and electronic vehicle systems such as antiblocking systems.
By having a closer look on these three case studies, the increasing importance and on-going diversification of cleanliness technology can be shown and also the challenging future requirements of cleanliness technology over the next few years can be derived.
Cleanliness TechnologyCleanroom TechnologyContamination ControlMedical DevicesPharmaceuticalsSemiconductorsSpace ExplorationFlight HardwareAutomotive
The Cascade Approach: Segregation by Airflow Design in stead of by Room Pressure

Ir. Frans W. Saurwalt Governmental inspection bodies as well as internal quality departments have enforced adherence to monitoring of room pressure as a critical aspect. And because of that, the pharmaceutical and medical
devices and healthcare industry puts a strong emphasis on controlling room pressure itself. As clean room construction becomes better and better, resulting in very limited leakage, active room pressure control
becomes more and more complex. With a narrow focus on room pressure control and monitoring, the broader contamination control perspective and a useful different approach is overlooked. Room pressure
control is only one aspect of the concept of segregation of zones of different classes. The broader view has many benefits. This approach is based on designing on airflow in stead of mere room pressure.
While citing ISO 14644-3, and -4 as well as the EU-GMP-vol 4 Annex 1 it can be demonstrated that there is a basis for designing an overflow / pressure cascade. This cascade approach when compared to various other
systems shows to have many benefits; increased protection of the controlled environment, less complexity, better stability, reduced energy-consumption and reduced costs.
SegregationRoom PressureAirflow/pressure CascadeStabilityWind AttackReduced Energy ConsumptionReduced Costs Of Installation
Clean Build Proocols - Concepts and Considerations

Andrew D. Watson A clean build protocol (CBP) is an essential component of a cleanroom
construction project. This paper provides guidance on how to develop and implement a
CBP in order to deliver a cleanroom that can successfully achieve its designated ISO
classification.
Cleanroom ConstructionClean Build Protocols (cbp)
MODERN PTFE MEMBRANE BASED HEPA/ULPA FILTERS FOR IMPROVED ENERGY SAVINGS AND RISK REDUCTION

Marc Schmidt, Ph.D., Sean O'Reilly, Mike Osborne, Ph.D., Jonathan Rajala, Ph.D. Strict demands are put on HEPA/ULPA filters that are installed as terminal filters in cleanrooms, isolators, workbenches etc. or as last filter stage in air handling units being upstream. They must continuously guarantee safe operation while predefined air quality requirements and energy efficiency are optimized. For that the filter media itself is of major importance.

Standard filter media for HEPA/ULPA filters so far had been fiberglass paper. Being free of boron filter media based on expanded Polytetrafluoroethylene (ePTFE) is used in microelectronics since decades. Based on latest developments in membrane technology, such as PAO compatibility, ePTFE and expanded Fluoro-Resin Membrane (eFRM) based HEPA filters are on their way to replace fiberglass-based filters.

This presentation describes how ePTFE and eFRM membrane media contributes to process safety and low-cost operation.

It sets out structure of modern ePTFE and eFRM membrane media, how these air filters provide significant reduction in energy consumption and risk.

It presents results of several studies on superior stability, durability and performance of ePTFE and eFRM media over traditional fiberglass media. Based on several tests regarding mechanical and chemical resistance as well as soot loading it is demonstrated that ePTFE and eFRM media offer a significant improvement in reducing media failure risk for a retained filter integrity.
Eptfe And Efrm Hepa FiltersRisk ReductionEnergy SavingsMechanical And Chemical Resistance