Tuesday, January 11, 2011

Environ monitoring essential in clean rooms

Supervising a clean room environment includes managing the air filter system, controlling the HVAC system, monitoring room temperature, humidity, pressure, gas presence and other factors.

Environmental Monitoring (E/M) is a programme designed to demonstrate the control of viable (living micro organisms) and non-viable particles in critical areas.  These areas include clean-rooms for drug fill/finish, formulation tank rooms, laminar flow hoods, biological safety hoods, isolators, glove boxes, moulding machines, kit assembly lines, intravenous (IV) compounding areas and sterile packaging.

Environmental monitoring provides important data on the quality of a process, processing environment, and final product, which can aid scientists in identifying and eliminating potential sources of contamination in cleanrooms and controlled environments.

A comprehensive environmental monitoring programme of clean rooms should include routine monitoring of both viable and non-viable airborne particulates. Although there is no requirement for the microbial identification of all contaminants present in these controlled environments, an environmental control programme shall include an appropriate level of bacteria identification obtained from sampling.

The areas generally monitored in a clean room environment include personnel, ventilation, building fabric and equipment. Both the airborne and surface contamination levels are tested. Testing should take place with the clean room in operation, however baseline data from cleaning validations and 'as built' conditions should also be collected.

Clean room surfaces are monitored either by a swabbing technique or by contact plates. Monitored surfaces should include personnel protective equipment (PPE), walls, floors and equipment. Swabbing has a reputation of giving a poor rate of recovery although there is the advantage that no media residue is left on the tested surface. After incubation, results from contact plates can be used to calculate the cfu per unit area.

The first step for correct bacterial identification, especially concerning a clean room isolate, is the Gram staining, since it can provide elucidative clues about the source of the microbial contamination. If microbial identification of isolates reveals Gram-positive cocci, the source of contamination can be derived from humans. If bacteria identification of isolates reveals Gram-positive rods, the source of contamination can be derived from dust or strains resistant to disinfectants. If bacterial identification of isolates reveals Gram-negative rods, the source of contamination can be derived from water or any moistened surface.

Microbial identification in pharmaceutical clean rooms is required for several reasons associated with quality assurance: determination of organisms from the manufacturing environment; bacteria identification from final product testing; demonstrating absence of named organisms from non-sterile products and water; quality control of fermentation stocks in biotechnology; and confirmation of test organisms in validation processes.

More and more, the Food and Drug Administration (FDA) is expecting bacterial identification to aid in determining the usual flora for a specific site, to evaluate the effectiveness of cleaning and to troubleshoot the source of contamination that can occur when action levels are exceeded or sterility tests become contaminated.

Maintaining the integrity of a cleanroom is a constant battle. The first step to deciding which method, or combination of methods, to employ is to identify the prime sources of contamination.

Companies who have their clean room facilities monitored do so to ensure their desired/required quality standards are met. The areas that are sampled in a manufacturer’s clean room include personnel, air and surfaces.

There are three prime sources of contamination through which the integrity of a cleanroom might be breached. First, there is the human element. Personnel are the biggest source of contamination in clean areas. While many processes might be automated, many situations remain whereby people are essential to the process. Controlling this source of contamination is available by a variety of methods, but human error can never be ruled out. This may occur at a variety of levels from the supply and cleaning of protective clothing, to the manner in which it is worn, and any other stipulations dependent upon the human factor.

Personnel harbour millions of bacteria, carrying them with them everywhere they go. Gowning is the most effective way to protect the cleanroom environment from ourselves. To asses the effectiveness of the gowning program personnel may be monitored on a regular basis for viable counts.  Personnel monitoring employs contact plates to assess microbial contamination of clean room personnel.

The second source is the equipment within the room or items brought into the room and the surface areas such as floors, walls and ceilings. Contamination can arise at any stage of the process, either as a result of human error or the failure of the cleaning regime to ensure that all surfaces remain contaminant-free.

A well developed environmental monitoring programme is a proactive way to assure the cleanliness of the manufacturing facility is maintained.

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