MICROORGANISMS IN CLEANROOMS
|Publication Date:||1 January 2006|
This Recommended Practice (RP) provides guidelines for the control and quantitative measurement of viable contamination in the air and on surfaces in environments that require control of such contamination. This includes areas designated as aseptic and those considered nonsterile. The procedures and techniques employed to achieve the desired level of microbial control are dependent on the level of bioburden that can be tolerated. This RP presents an introduction to the currently accepted methods for bioburden control and environmental monitoring as well as the devices available for the quantification of airborne and surface viable contamination.
This document also describes disinfectants, their lethality spectrum, and techniques for their application.
BACKGROUND AND PURPOSE
Technology advancements in the electronics, medical device, and
• Molecular contamination-the undesired presence of chemicals or elements in a product or device
• Particulate contamination-the presence of material that can cause defects due to its physical presence
• Electrostatic contamination-the presence of excess or unwanted electrical charge
• Microbial contamination-the unwanted presence of microorganisms or their metabolic byproducts in a product or environment
Controlled environments and cleanrooms have evolved as the primary method for controlling contamination. Cleanrooms can be designed and maintained to control any or all forms of contamination. The control of microorganisms is important in virtually any cleanroom, regardless of industry, due to the particulate nature of these organisms. The control of microorganisms is especially critical in the medical device, pharmaceutical, and food industries due to the nature of materials produced and their end use. Microorganisms found in cleanrooms are typically bacteria or fungi. Because viruses require a living cell to survive and reproduce they typically are controlled if the number of bacteria are kept in check. Microorganisms are capable of growing and reproducing in a wide variety of environments and creating effects that range from pathogenic or lethal to beneficial, depending on the application. In a cleanroom, the presence of any bacteria is problematic even if considered merely as particles.
The evaluation of microbial contamination should consider two components. The first is the number of viable bacteria that can be demonstrated from the test subject. This should include some type of determination of the feasibility of obtaining an accurate estimate of these microorganisms. Secondly, the type (identity) of the organism present can have a profound impact on the effectiveness of any control program. It is a good practice to try to determine the ordinary population of microorganisms in the controlled environment.
The ability of microorganisms to grow and thrive almost anywhere makes them a challenge to control in the cleanroom. Their ability to cause illness or disrupt processes through physical exposure to the product or the effect of toxins or other metabolites make their removal of critical importance in most cleanrooms. In spite of their considerable adaptive properties, most bacteria found in cleanrooms are not permanent residents but are transported into the cleanroom from one of three main sources:
• The environment or the air and space around the cleanroom. The number and type of microorganisms in an environment can vary greatly over time, with the season or with the availability of nutrients.
• Cleanroom personnel. This is the most significant source, as the extensive microbial population associated with every human poses a significant threat to the product.
• Raw materials used in the product, cleaning solutions, and process equipment.