Chapter 9 By the end of this chapter, you will be able to: l Define the terms cleaning, decontamination, disinfection l List the factors that affect disinfection l Describe the aims of a cleaning schedule l Explain the different cleaning schedules Introduction In this chapter we will examine the different types of cleaning that take place in an aseptic suite and explain the differences between them. We will also take a look at how to clean work zones and cleanrooms. Definitions Decontamination Disinfection The process of dirt removal. The removal of a contaminant. This can be chemical or microbiological but generally it refers to chemical. Examples include a spillage from a cytotoxic drug or glucose from a PN preparation. The process of reducing the number of viable micro-organisms. Chapter 9: 1
Aseptic Processing Why do we need clean rooms? The cleaning, decontamination and disinfection processes are interlinked and may occur simultaneously. will reduce the levels of micro-organisms. and disinfection may also remove chemical contamination. A cleanroom fitted with filters should in theory not need cleaning, but in practice there are many potential sources of contamination within each cleanroom. It is therefore essential to clean the cleanroom to remove the contamination and increase the chance of the disinfectant working. Training a cleanroom is a complicated task requiring trained personnel, specialised equipment and materials and structured procedures. All personnel must be trained in cleanroom procedures and must follow proper gowning procedures before entering the cleanroom. Cleanroom apparel should be compatible with the cleaning agents being used. Schedule Premises The table below shows a typical cleaning schedule. Area Ceilings Walls Floors Benches Doors Chairs Cabinet exterior Frequency of Monthly Monthly Daily Daily Daily Daily Daily Order of cleaning: Once the correct cleaning equipment has been selected the room cleaning should start with the low priorities first. For example, begin cleaning the ceiling, walls and floors, then followed by equipment, as follows: Ceilings Walls Floors Benches Doors Chairs Cabinet/isolator exterior The room should be cleaned from the cleanest area within the room to the dirtiest following your Standard Operating Procedures, e.g. innermost areas, working outward to the door. In general, cleaning should begin in the areas requiring the most critical level of cleanliness and proceed towards areas with less critical requirements. When cleaning walls, wiping should be carried out in a downwards direction only so that particles are pushed down to the floor where they can be more easily removed. Please note: the frequencies shown may very in accordance with your local procedure. 2 Chapter 9:
Chapter 9 Here are some factors to consider before setting up a cleaning schedule: l Horizontal surfaces attract more contamination than vertical ones. l Lower surfaces attract more contamination than higher ones. l People make contact with the doors much more than the walls. l There are areas in every cleanroom that may accumulate dirt more than others. l Friction from work clothes and a very dry atmosphere creates static. Static can attract dust. The aim for walls, floors, ceilings and work surfaces is to ensure that they are as clean as possible with any microbial contamination kept to a minimum. Ideally cleaning should occur at the end of a working day to give plenty of time for the resulting air disturbance to subside before the room is used again. should also be carried out in slow manner to avoid turbulence in the air which would create additional dust particles. In a manufacturing environment the main concerns when considering cleaning a clean room are: l Particulates: from people, equipment, filtration defects and consumables. l Viable organisms: from people and containers l Chemical cross contamination: from spillages and cross contamination from products. Test Yourself Facts Fill in the blanks in the following sentences:.... surfaces get more contaminated than.... ones..... surfaces get more contaminated than.... ones. People make contact with the........ much more than the............ from work clothes and a very dry atmosphere creates..... Static can attract...... Chapter 9: Quality Systems for Operators 3
Aseptic Processing Agents agents can be categorised as: l soil removers; l killers of micro-organisms; and l controllers of electrostatic charges. When units are first commissioned a series of initial clean downs are performed to remove surface dirt prior to disinfection/cleaning schedules. These are some of the common disinfectants used and their activity, bactericidal, fungicidal, virucidal and sporicidal. Comparison of disinfectants Table Disinfectant Type Activity Bactericidal Fungicidal Virucidal Sporicidal Alcohols Good Good Good None Aldehydes Good Good Good Good Amphoteric Surfactant Good Fair Fair None Biguanide Good Fair Good None Chlorine Dioxide/Quat Blend Good Good Good Good Hypochlorites Good Good Good Fair Hydrogen Peroxide /Peracetic Blend Good Good Good Good Phenolic Compound Good Good Fair None Quaternary Ammonium Compounds Good Good Good None Table supplied by Pharmaceutical International, information from Shield Medicare article Step by step selection of clean room disinfectants. Glossary Bactericidal Kills bacteria Fungicidal Kills fungi Virucidal Kills viruses Sporicidal Kills spores Quat Blend Blended mixture of quaternary ammonium compounds 4 Chapter 9:
Chapter 9 Wiping of surfaces should be done: with a lint free non shedding sterile mop or cloth. with sterile (in Grade A and B rooms) detergents and chemicals. Images supplied by Pharmaceutical International Wiping removes contaminants and prevents any deposits being left. It removes spores (which are not killed by alcohol). The pressure of wiping may also kill some micro-organisms. Disinfection Once surfaces have been cleaned they should be disinfected. Disinfectants should always be used in accordance with the manufacturer s instructions and at the right dilution. Dilute disinfectants should not be stored and should be freshly made up each time they are required. Disinfectants may be rotated to prevent the development of disinfectant resistant strains of microbes. solutions must be used in accordance with your local schedule. These may also be changed on a rotational basis to avoid resistance to micro organisms if they include disinfectants. Disinfecting agents need time to work and local procedures need to be followed to ensure that the disinfectant stays in contact with the surface for sufficient time for microorganisms to be killed. Typically the recommendation is that the surface needs to be wetted for 2 minutes. Note: Disinfection is sometimes called sanitisation. This term is popular in industry and is used in the Orange Guide. Remember: Disinfection is only effective if the surface to be treated is already clean. Disinfectant will work better if the surface is clean and has a low biological contamination level (bioburden). Disinfectants can be inactivated by dirt. Dirt (especially oil or greasy films and protein like matter) can also protect microbes against the action of disinfectants. Chapter 9: Quality Systems for Operators 5
Aseptic Processing Disinfection also depends on the following factors: Temperature Microbes flourish at warmer temperatures Saturation and penetration of the cell wall sufficient disinfectant must be used and time allowed to take effect. Surface and the bioburden of the surface surfaces should be smooth and impervious to enable effective cleaning and to reduce the risk of microbial growth. Reducing the bioburden through cleaning helps to make disinfection more effective. Dirty surfaces are difficult to disinfect. Concentration of the chemical agent the correct concentration of cleaning solution must be used for effective disinfection is a non destructive mechanical action to loosen and remove contaminants from the surface. By lessening the level of particulates, microbes and residues on the surface, the disinfection effort becomes simpler and more effective. Through cleaning, the bioburden (the number of micro organisms with which an object is contaminated) is reduced. laminar flow cabinets and isolators Both laminar flow and isolator cabinets need to be cleaned and sanitised (disinfected) before use (sessional cleaning). To carry out the cleaning, wear the correct gown and sterile gloves. Wipe your gloved hands with a sterile wipe and spray using the correct alcohol spray before starting. Sessional LAFC Clean Image supplied by Pharmaceutical International ph Most bacteria survive best at neutral ph levels (around ph7), so changing this value through disinfection will help Remember l is sometimes confused with disinfecting but they are not the same. l removes the contamination from the surface. l Disinfecting attempts to destroy any viable cells on or in the surface. The laminar flow cabinet light needs to be switched on and the airflow checked before starting the cleaning process. 6 Chapter 9:
Chapter 9 Isolator Clean Down Each surface is wiped from the back to the front, overlapping the strokes, using different faces of the wipe. Opening the isolator for cleaning gives easier access but must be followed by disinfection or gassing in the closed state and leak testing. The isolator must be switched off before opening. This is not normally done unless it is a full clean or an emergency. Use a clean sterile wipe for each surface that you clean in the cabinet and turn the wipe to use a fresh surface regularly. Sessional Isolator Clean Each surface is wiped from the back to the front, overlapping the strokes, using different faces of the wipe. Use a clean sterile wipe for each surface that you clean in the cabinet and turn the wipe to use a fresh surface regularly. the isolator involves cleaning the workspace, transfer hatches and internal surfaces. Chapter 9: Quality Systems for Operators 7
Aseptic Processing When cleaning isolators used for the preparation of cytotoxic drugs, suitable precautions should be taken by the operator. This includes a mask and eye protection as well as the usual gown and gloves. Further Reading: For more information on cytotoxics see Chapter 19 Preparation of Cytotoxics. Before you exit the clean room make sure you do the following: l Remove your gloves and immediately decontaminate your hands using alcohol hand rub. l Discard your gloves in the yellow clinical waste bin in the area you are working. l Make sure the door closes properly behind you. l Remove masks and discard. l Remove your cleanroom garments and place in the laundry. (Any contaminated clothing should be bagged separately). l Remove your hat and discard. Further Reading: For more information on how to dispose of waste correctly see Chapter 14 Waste Disposal. Note: The clean down/exit procedure is carried out at the end of a session and not after completing a product. Remember l Each surface is wiped from the back to the front, overlapping the strokes, using different faces of the wipe. l A clean wipe should be used for each surface and then discarded. l For aseptic work, cleaning is always combined with or followed by disinfection. l The work zone of the isolator or laminar air flow cabinet should be cleaned between products. Equipment l All cleaning equipment and implements should be thoroughly cleaned after use and stored in a clean, dry condition. l Excess liquid use should be avoided. l If surfaces are wiped, a minimum contact time of 2 minutes with the disinfectant should be allowed. l Any spillage should be cleaned up immediately and effectively. l If there is a risk of microbial contamination, the cleaned-up area or surface should then be disinfected. l After use, all manufacturing equipment must be thoroughly cleaned following a written procedure. l It may be necessary to strip equipment down before cleaning it. l The written procedure should always be followed. l Once equipment has been cleaned, steps should be taken to ensure it cannot become re-contaminated. Monitoring Levels of contamination should be regularly monitored to ensure that the cleaning procedures are working properly. 8 Chapter 9:
Chapter 9 Activity Have a look at the clean room images below. Make a list of the potential causes of contamination in the images below. Potential sources of contamination: There are at least eight things that can cause contamination in this cleanroom. If you have found more than eight, well done. Chapter 9: Quality Systems for Operators 9
Aseptic Processing Questions Q1 What is the difference between cleaning and disinfecting? : Disinfecting: (4) Q2 When cleaning the cleanroom, what is the recommended order in which you should clean the various surfaces prior to disinfection? (7) 10 Chapter 9:
Chapter 9 Q3 Why should the work zone be cleaned before it is disinfected? (3) Chapter 9: Quality Systems for Operators 11
Aseptic Processing 12 Chapter 9: