While filtration, special surfaces, and operating procedures establish and maintain cleanliness levels in a cleanroom, routine cleaning and maintenance are vital to keeping a facility clean. Inadequate or sloppy housekeeping can result in reduced product yields, compromised products or experiments, or higher operating costs.
In a survey from the editors of Controlled Environments, representatives of companies that supply cleanroom consumables shared advice on cleaning practices, products, and strategies. They also discussed cleaning challenges and the advantages and disadvantages of using company employees to clean versus using an outside cleaning service.
The procedure for cleaning a controlled environment will differ according to the individual company, the processes occurring in the clean facility, and cleanliness levels required. No matter the specifications, though, there are some universal steps to follow, the experts say. Each facility should have written standard operating procedures and checklists for different cleaning frequencies (by shift, daily, weekly, etc.).
David Nobile, senior technical services engineer from Contec Inc., Spartanburg, S.C., suggests some basic protocols that every facility should follow when establishing a cleaning procedure:
• Environmental monitoring (EM) and identification of contaminants (viable and/or non-viable).
• Select cleaning chemicals and disinfectants based on the results of the EM program.
• Select cleaning materials appropriate for the class cleanroom and the applications/uses.
• Determine that the materials selected perform as expected or required.
• Consult recommended practices for protocols and cleaning frequency from the Institute of Environmental Sciences and Technology (IEST).
• Write protocols based on the preceding information.
• Conduct cleaning verification tests.
• Revise protocols if necessary and re-verify.
• Train staff.
• Implement cleaning protocols.
• Self-audit to ensure protocols are followed.
Within a facility, different areas will require different cleaning strategies. Many variables must be considered. Baseline particle counts should establish the cleaning standard.
Eric Swainbank, sales and marketing manager for Terrell, Texas-based Degage Corp., identified three areas that require different levels of cleanliness. In gowning areas, cleanliness levels may be less strict, but the area will require more frequent cleaning. Frequent cleaning is also required in areas where products cannot be contaminated, but can transfer contamination. In production areas, cleaning must be done to the highest level.
“To establish a cleaning process and schedule, the above items need to be considered from the baseline test all the way down to the critically clean areas and the activities that take place in each one,” Swainbank says.
Different levels, different demands
The methods, materials, and frequency may be quite different for cleaning a Class 1 cleanroom versus a Class 7 cleanroom.
“The products used are vastly different in material and the method in which they are used,” says Seb Russo, vice president of sales and marketing at Connecticut Clean Room Corp., Bristol, Conn. “Is it an aseptic or non-aseptic room? Is the process sensitive to cleaning chemicals? Does the room contain a process or is it just for testing? A knowledgeable cleanroom product distributor can help in determining what products to use.”
Nobile says the methods for cleaning different environments are the same, or nearly so. The difference lies in the consumables used, and the frequency with which they are used. “As a general rule, the cleaner the environment, the more inherently clean the consumable,” he explains. “As example, while a wipe made from polyester and cellulose fibers is suitable for an ISO 7 environment, it wouldn’t be used in an ISO 4 environment, where pure synthetic wipes would typically be used.”
While cleaner environments are typically cleaned more frequently, Nobile adds, this is not always the case. “A great deal depends on the activities within the environment and the various risks to the products produced within them.”
“In Class 100,000—depending on the use of the room—you might be changing it and mopping the floors once a week,” says Cathy Albano, marketing and sales manager for Liberty Industries, East Berlin, Conn. “In a Class 1 cleanroom—because of the protocol—it needs to be done after every shift or at the end of every day versus every week. The cleaner the cleanroom, the more you need to clean it to make sure that it stays clean.”
For pharmaceutical facilities, U.S. Food and Drug Administration (FDA) and United States Pharmacopeia (USP) standards for disinfection establish cleaning protocols.
Developing effective, compliant disinfection procedures for the facilities is where the users of disinfectants sometimes get in trouble, comments Christopher Fournier, vice president of marketing at Mar Cor Purification, Lowell, Mass. He recommends that users follow the recommendations set forth by the USP 29 NF-24 <1072>, to get the correct efficacy, and to simplify the protocols. USP <1072> classifies biocides for cleanroom disinfection and provides definitions on decontamination techniques, the use of disinfectants, sanitizing agents, sporicidal agents, and sterilants. It outlines the factors affecting and the process of selecting an appropriate disinfectant for a pharmaceutical manufacturing environment.
When considering the risk versus the benefits, Fournier says, peracetic acid is one of the better choices for cleanroom disinfection and is being used by more biopharmaceutical companies.
Peracetic acid is validated as a sporicidal agent and sterilant, but is not toxic, carcinogenic, mutagenic, or hazardous. It can be used in very low concentrations (less than 1%), as a liquid for manual disinfection procedures, or in vapor form as an airborne disinfection agent in cleanrooms and aseptic areas.
The bare necessities
The supplies needed for cleaning a facility will vary according to the cleanroom’s classification and purpose, but there are certain materials that every facility should use.
Cleaning a home requires a collection of mops, vacuums, wipers, and cleaning agents. Similarly, cleanrooms require different tools for different cleaning tasks. Wipes and swabs clean small areas; mops are dedicated to larger surfaces. Cleaning solutions should be formulated to the task. Vacuum cleaners, non-shedding mops, and sticky rollers are other necessities.
“All cleanrooms should have the basic materials used for wipe-downs, and floor and wall maintenance to follow the standards for each designation,” says Russo. “This can only be answered by the classification and the process that is going on in the room.”
Swainbank recommends several items that all cleanrooms should stock. “The must-have consumables to maintain cleanliness are non-shedding wipes, sticky mats, mops, HEPA filter vacuums, disinfectant sprays, cleanroom smocks, gowns, gloves and shoe covers, cleanroom trash bags, and trash cans,” he says.
Since a cleanroom may have small corners and edges that can be missed when mopping floors and wiping down walls, more specialized equipment sometimes is required.
“One thing that should not be overlooked when maintaining the cleanliness of a cleanroom is the importance of a swab,” notes David Perkins, senior vice president of sales for medical and critical environments at Puritan Medical Products, Guilford, Maine. “Cleaning walls, floors, and other flat surfaces can give the appearance of a clean work environment but there are many nooks and crannies where the use of a swab is critical. The cleaning process should include areas that can accumulate particulates in hard to reach areas that only a swab can effectively clean.”
Perkins identifies machinery and equipment, floor drains, and air handling systems as areas suitable for cleaning with swabs. In addition, swabs can be used to test for molds, bacteria, total organic carbon, and proteins.
Garments are an important tool in a cleanroom, especially to cover workers’ feet so that particles are not tracked inside.
“Shoe covers are ‘must-have’ consumables in order to maintain cleanliness in a cleanroom. Out of everything people wear, shoes are by far the dirtiest and most likely to have things stuck to them that can fall off,” says Jeff Foster, product manager for Shoe Inn, Sparks, Nev. “Moreover, according to one recent study, researchers found at least nine different types of bacteria on peoples’ shoes. Shoe covers prevent these types of contaminants from entering and being left behind.”
Hire a service, or DIY?
Who is best suited to perform housekeeping in a clean environment? Those that work in the cleanroom, a special in-house cleaning team, or an outside cleaning service? There are advantages and disadvantages to each, say cleaning supply representatives.
An in-house staff will be most familiar with the facility equipment and, since they are already employed by the company, it is easy to keep track of their progress. However, while the company employees may be specialists in the manufacturing, technical, or research work performed in the cleanroom, they may lack the skills and knowledge to properly clean the area. Adding cleaning responsibilities will reduce the amount of time available for performing assigned tasks. The lack of third-party verification is another issue.
“The biggest disadvantage of outside [cleaners] is lack of knowledge as to the machines, the chemicals, the equipment and the procedures,” says Colleen Cole, Josco Products, Austin, Texas. “The best advantage is they will have a routine and follow it.”
As for in-house staff, an advantage is that they are taking care of the area where they have to do their work, and as such they “take pride in their workspace and understand the material flow within that workspace,” notes Perkins. “The downside to using in-house cleanroom staff is it can be easy to become complacent and usually the cleaning takes place at the end of a potentially long work day.”
“In-house staff can be monitored and adjusted easily, while an outside service may have more experience,” adds Mike Dougherty, sales and marketing, Perfex Corp., Poland, N.Y.
An obvious advantage of using in-house cleaning is cost, says Russo. While using and outside contractor would cost more, he says. “Contractual accountability, certification, and taking the guess work away from the company are advantages.”
“The fact that cleaning cleanrooms is so difficult and underappreciated, it can also result in poor adherence to cleaning protocols and inconsistent results, whether done by direct employees or an outside contractor,” says Sullivan. “But this condition is greatly exacerbated by a lack of sufficient supervision and high worker turnover that is not uncommon when using an outside cleaning service.”
Cleaning contamination that cannot be seen is a challenge. The work can be difficult, especially when performed in garments, gloves, masks, and head coverings. The best strategies, the experts say, is to establish proper protocols, provide the proper cleaning tools, and communicate the importance of the housekeeping processes.
“This goes to the heart of the manufacturing operation: What do we (the manufacturer) make? Why do we make it in a cleanroom? What are the risks to our products? Why do we follow the cleaning protocols as we do? What is the impact of my role in all this?” says Nobile. “While these topics may seem a bit ‘touchy-feely’ and one might assume cleaning staff should know the answers to these questions, the reality is far different. Once knowledge and understanding of the need for cleaning is achieved, consistent and exemplary results are possible.”
The Institute of Environmental Sciences and Technology (IEST) offers voluntary standards on cleanroom practices, including cleaning and maintenance.
IEST-RP-CC018.4: Cleanroom Housekeeping: Operating and Monitoring Procedures (October 2007)
Provides guidance for maintaining a cleanroom at the level for which it was designed. The document is intended as a guide for establishing appropriate housekeeping procedures and provides test procedures to establish the frequency of housekeeping and monitoring its effectiveness.
IEST-RP-CC004.3: Evaluating Wiping Materials Used in Cleanrooms and Other Controlled Environments (August 2004)
Describes methods for evaluating or testing wipers used in cleanrooms and other controlled environments for characteristics related to both cleanliness and function.
IEST-RP-CC016.2: The Rate of Deposition of Nonvolatile Residue in Cleanrooms (November 2002)
Provides a uniform method and basis for defining the rates of deposition of nonvolatile residue (NVR) and other forms of molecular contamination on surfaces in cleanrooms.
IEST-RP-CC026.2: Cleanroom Operations (September 2004)
Provides guidance for maintaining the integrity of the cleanroom during ancillary operations including the preparation of supplies and materials, modification of the facility, and installation and repair of equipment.
United States Pharmacopeia
USP 29 NF-24 <1072>
This standard classifies the biocide and gives clear definitions on decontamination techniques, the use of disinfectants, sanitizing agents, sporicidal agents, and sterilants.
U.S. Food and Drug Administration
Guidance for Industry, Sterile Drug Products Produced by Aseptic Processing- Current Good Manufacturing Practice (September 2004)
Part A. Environmental Monitoring, Point 3. Disinfection Efficacy states that a sound disinfection program should include the use of a sporicidal agent.
MaryBeth DiDonna is the Managing Editor of Controlled Environments.
This article appeared in the September 2012 issue of Controlled Environments.