By Crystal M. Booth, PSC Biotech
Humans are the primary source of contamination in cleanrooms. Cleanrooms are designed to aid in the protection of the items being manufactured from environmental contaminants as much as possible. To protect the items being manufactured from human contamination, special gowning requirements are necessary.
This is part 1 of a two-part series. This article will focus on an overview of cleanroom gowning as it pertains to aseptic manufacturing of medicinal products and the updates to gowning requirements in the revised Annex 1 document, The Rules Governing Medicinal Products in the European Union Volume 4 EU Guidelines for Good Manufacturing Practice for Medicinal Products for Human and Veterinary Use, which was published on Aug. 22, 2022. Part 2 will focus on establishing an aseptic personnel gowning program.
Cleanroom gowning greatly reduces the levels and types of microorganisms released by personnel. Eighty to 90 percent of normal microbial flora identified in a cleanroom environment is generated from humans.1 The primary purpose of cleanroom gowning is to protect products and the processing environment from airborne contamination.2
Annex 1 (2022), Manufacture of Sterile Medicinal Products, produced by the European Commission EudraLex, is the most descriptive guidance on cleanroom gowning. Annex 1 provides the following guidance to companies regarding cleanroom gowning.3
- Only the minimum number of personnel required should be present in clean areas.3
- All personnel employed in clean areas should receive regular training in disciplines relevant to the correct manufacture of sterile products. This training should include reference to hygiene and to the basic elements of microbiology, with specific focus on cleanroom practices, contamination control, aseptic techniques, and the protection of sterile products. In addition, training should include safety implications for patients.3
- Unqualified personnel should not enter grade B or grade A cleanrooms in operation. In exceptional cases, there should be established written procedures outlining the process by which unqualified personnel are brought into grade B and grade A areas.3
- Staff who have been engaged in the processing of human tissue, animal tissue materials, or cultures of microorganisms (other than those used in the current manufacturing process) should not enter sterile product areas unless rigorous and clearly defined entry procedures have been followed.3
- High standards of personal hygiene and cleanliness are essential. Personnel involved in the manufacture of sterile products should be instructed to report any specific health conditions or ailments to management. Health conditions and actions to be taken regarding personnel who could be introducing an undue microbial hazard should be provided by the designated competent person and described in procedures.3
- Wristwatches, makeup, jewelry, and other personal items such as mobile phones and any other nonessential items should not be allowed in clean areas. Manufacturer-provided mobile phones, tablets, or other electronic devices may be allowed, provided they are appropriately disinfected and included in the contamination control strategy.3
- Cleanroom gowning and handwashing should follow written procedures designed to minimize contamination of cleanroom clothing and/or the transfer of contaminants.3
- The clothing and its quality should be appropriate for the process and the grade of the working area. It should be worn in such a way as to protect the product from contamination.3
- Outdoor clothing (including socks) should not be brought into changing rooms leading to grade B and C rooms. Personal underwear is OK.3
- Single or two-piece facility trouser suits, covering the full length of the arms and legs, and facility socks covering the feet, should be worn before entering changing rooms for grades B and C. 3
- Every worker in a grade A/B area should gown in clean, sterilized protective garments, which include eye coverings and face masks. Annex 1 also states that the maximum amount of time a garment should be worn before replacement during a shift should be defined as part of the garment qualification.3
- Gloves should be regularly disinfected during operations. In addition, gloves and gowns should be changed immediately if they become damaged or present any risk to product contamination.3
- Clean area clothing should be cleaned and handled in such a way that it does not gather additional contaminants that can later be shed. Reusable clean area clothing should be cleaned in a laundry facility adequately separated from production using a qualified process, so it does not introduce contamination or cross-contamination.3
In addition to providing information on clothing, jewelry, personal hygiene, and training, Annex 1 provides a breakdown of the gowning that should be implemented for each environmental grade classification. The clothing required for each cleanroom grade listed in Annex 1 is described below.3
- Grade D: “Hair, beards, and moustaches should be covered. A general protective suit and appropriately disinfected shoes or overshoes should be worn. Appropriate measures should be taken to avoid any ingress of contaminants from outside the clean area.”3
- Grade C: “Hair, beards, and moustaches should be covered. A single or two-piece trouser suit gathered at the wrists and with high neck and appropriately disinfected shoes or overshoes should be worn. They should minimize the shedding of fibers and particles”3
- Grade A/B: Grade B (including access/interventions into grade A): appropriate garments that are dedicated for use under a sterilized suit should be worn before gowning. Appropriately sterilized, non-powdered, rubber or plastic gloves should be worn while donning the sterile garments. Sterile headgear should enclose all hair (including facial hair) and where separate from the rest of the gown, it should be tucked into the neck of the sterile suit. A sterile face mask and sterile eye coverings (e.g., goggles) should be worn to cover and enclose all facial skin and prevent the shedding of droplets and particles. Appropriate sterilized footwear (e.g., over-boots) should be worn. Trouser legs should be tucked inside the footwear. Garment sleeves should be tucked into a second pair of sterile gloves worn over the pair worn while donning the gown. The protective clothing should minimize shedding of fibers or particles and retain particles shed by the body. The particle shedding and the particle retention efficiencies of the garments should be assessed during the garment qualification. Garments should be packed and folded in such a way as to allow operators to don the gown without contacting the outer surface of the garment and to prevent the garment from touching the floor. 3
- Additional gowning, including gloves and face mask, may be required in grade C and D areas when performing activities considered to be a contamination risk as defined by the contamination control strategy (CCS). 3
- “Cleanroom gowning should be performed in change rooms of an appropriate cleanliness grade to ensure gown cleanliness is maintained. Outdoor clothing including socks (other than personal underwear) should not be brought into changing rooms leading directly to grade B and C areas. Single or two-piece facility trouser suits, covering the full length of the arms and the legs, and facility socks covering the feet, should be worn before entry to change rooms for grades B and C. Facility suits and socks should not present a risk of contamination to the gowning area or processes.” 3
Annex 1 (2022) also states that “garments should be visually checked for cleanliness and integrity immediately prior to and after gowning. Gown integrity should also be checked upon exit. For sterilized garments and eye coverings, particular attention should be taken to ensure they have been subject to the sterilization process, are within their specified hold time and that the packaging is visually inspected to ensure it is integral before use. Reusable garments (including eye coverings) should be replaced if damage is identified, or at a set frequency that is determined during qualification studies. The qualification of garments should consider any necessary garment testing requirements, including damage to garments that may not be identified by visual inspection alone. Every operator entering grade B or A areas should gown into clean, sterilized protective garments (including eye coverings and masks) of an appropriate size at each entry. The maximum period for which the sterilized gown may be worn before replacement during a shift should be defined as part of the garment qualification. Gloves should be regularly disinfected during operations. Garments and gloves should be changed immediately if they become damaged and present any risk of product contamination.”3
There are many different types of gowning supplies available on the market. The types of cleanroom gowns and PPE worn by personnel should be appropriate for the areas in which they work. Gowning supplies can be disposable or reusable, with various types of materials available. It is often easier to purchase disposable gowning supplies, but this can become costly.
Reusable gowns must be managed to ensure the integrity of the garment is maintained through multiple washing and sterilization cycles. The washing and sterilization processes must be validated.2 Pharmaceutical laundry services are commercially available that have validated processes for reusable gowns. These services help to ease some of the burden on the manufacturer. The launderer will manage how many times items can be laundered and how many times the items have been laundered and will manage the replacement of the items when needed. Associates at the company should still pay close attention to their gowning supplies and not use items that are damaged or are showing visible signs of wear. The associate should report any damage noticed on the gowning supplies to their management so that the launderer can be notified of the incident to correct the issue and prevent future occurrences.
Once a source of gowning supplies has been properly secured, it is important to note that only qualified personnel should enter a cleanroom. Companies should develop programs to prevent unauthorized personnel from entering cleanroom environments. One suggested way to accomplish this control is using badge access systems. Personnel who have not completed the required training courses would not be granted badge access to the cleanroom.
Gowning For Grade D Areas
Grade D areas are used for less critical operations in the manufacturing process. They are considered ISO Class 8 environments. Components may be handled or prepared in the grade D area. The grade D area is also the minimum allowed background for aseptic filling within an isolator environment.
Gowning procedures may vary slightly from company to company. It is suggested that in preparation for gowning into a grade D area, employees follow these steps: Remove all jewelry and makeup and wash their hands. Don plant-issued scrubs and socks for entry into the grade D area and sanitize safety glasses. Don a hairnet, beard cover (if required), and safety glasses. Ensure that no hair is exposed prior to entering the grade D area. Don shoe covers over safety shoes one foot at a time while crossing over a demarcation line separating a “clean side” of the room from the “dirty side” of the room. Sanitize hands and don a pair of sterile gloves, ensuring that no skin is exposed. Sanitize the gloved hands and then proceed into the grade D area.
Gowning For Grade C Areas
Grade C areas are used for less critical operations in the manufacturing process. They are considered ISO Class 8 environments in the dynamic state and ISO Class 7 environment in the static state. Typical applications for grade C areas include preparation of materials to be filtered and filling of products that will undergo terminal sterilization.
When moving from the grade D area, a suggested procedure is to select an appropriately sized coverall and pair of boot covers. Don the coveralls, taking care not to let the gown touch the floor. Zip up the coverall completely and snap all buttons. Don the boot covers one foot at a time while crossing over a demarcation line separating a “clean side” of the room from the “dirty side” of the room. Check the mirror to ensure no hair is exposed and sanitize hands prior to proceeding into the grade C area.
Gowning For Grades B/A Areas
Grade B areas are the background environments for the traditional grade A areas. In instances where isolators are utilized, the background environments may be downgraded. Grade B environments are typically used to protect the grade A aseptic filling operations or for the background area for sterility testing in a grade A biological safety cabinet. Grade B areas in the dynamic state are also considered ISO Class 7 areas.
Face masks, hoods, protective goggles, gloves, coveralls, and boots utilized in aseptic processing must be sterile and made of non-particle shedding material.3 Care should be taken that no skin or hair (including facial hair) is exposed in the aseptic area.4
A recommended gowning protocol for the grade B area begins by moving into a grade B area transition gowning room. Remove safety glasses and sanitize gloved hands. Don an additional hair net and beard cover (if required) over the existing ones. Using the mirror, check and adjust hair covers to ensure that no hair is exposed. Sanitize hands again with a suitable disinfectant. Don a second pair of sterile, powder-free gloves. Sanitize the crossover bench. Obtain an appropriately sized sterile hood, sterile coveralls, sterile goggles, sterile face mask, and sterile boot covers. Sanitize the exterior of the packages and place the items on the crossover bench.
After sanitizing hands, don a sterile face mask. The face mask should completely cover the mouth, nose, chin, and cheeks. Sanitize gloved hands with a suitable disinfectant. Remove the sterile hood from the packaging by handling the inside of the hood. Don the hood by handling the hood only from the inside. Sanitize gloved hands and remove the sterile coveralls from the package. Only handle the inside portion of the garment. Don the garment by not allowing the garment to touch the floor and by touching only the internal pieces of the coveralls. Carefully tuck the hood into the coveralls and then sanitize gloved hands. Zip up the garment, taking care to only touch the zipper and not the exterior of the gown. Snap all the buttons on the collar and sanitize the gloved hands again.
Don one sterile boot cover over one existing shoe cover while transitioning the foot to the grade B side of the bench. Do not allow the sterile boot to encounter the “dirty side” of the bench. Follow the same process with the other foot. Pull the sterile boot cover legs up over coverall legs and snap all the buttons. Using the mirror, check and adjust hair covers to ensure that no hair is exposed. Sanitize gloved hands. Don sterile goggles that completely cover the remaining exposed surface of the face. Sanitize gloved hands.
Conduct a final self-inspection in the mirror to ensure that no hair is exposed and that all items are tucked in properly. Don the final pair of sterile gloves and sanitize gloved hands. Ensure the sterile gloves are covering the coverall’s wrists. Sanitize gloved hands and enter the grade B clean area. Ideally, the doors should be arranged so that one can back through the door to maintain the asepsis of the sterile gloves.
Grade A areas are critical areas for aseptic processing. Typical applications include open handling of product, aseptic filling operations, and sterility testing, to name a few. Grade A areas are also considered ISO Class 5 environments. Modern technology, such as isolators and RABS (restricted access barrier systems), are engineering people out of the grade A areas.
“Gloves should be regularly disinfected during operations. Garments and gloves should be changed immediately if they become damaged and present any risk of product contamination.”3
A vigilant and responsive personnel monitoring program is essential for aseptically manufactured products. The updated Annex 1 document, The Rules Governing Medicinal Products in the European Union Volume 4 EU Guidelines for Good Manufacturing Practice for Medicinal Products for Human and Veterinary Use, has a few changes regarding cleanroom gowning, including more detail on where, when, and how to monitor personnel, as well as proposed monitoring limits.
By adhering to regulatory requirements and following the applicable site procedures, firms may avoid regulatory observations concerning microbial controls in respect to cleanroom gowning.
- Hayes, B. (2015) Managing Aseptic Gowning within Classified Environments. Clean Room Technology, 3. Accessed on October 30, 2022 at: https://cleanroomtechnology.com/news/article_page/Managing_aseptic_gowning_within_
- Ljungqvist, B. and B. Reinmuller (2005) Aseptic Production, Gowning Systems, and Airborne Contaminants. Advanstar Communications, Data and Review. Accessed on October 30, 2022 at: http://alfresco-static-files.s3.amazonaws.com/alfresco_images/pharma/2014/08/22/45de5f72-d0e2-4a54-804d-30f770d02589/article-160408.pdf
- Annex 1 (2022) The Rules Governing Medicinal Products in the European Union - EU Guidelines to Good Manufacturing Practice, Medicinal Products for Human and Veterinary Use. Annex 1- Manufacture of Sterile Medicinal Products. European Commission EudraLex, 4.
- United States Pharmacopeia (USP) <1116> Microbiological Evaluation of Cleanrooms and Other Controlled Environments.
About the Author:
Crystal M. Booth, M.M., ASQ-CQE, PMI-PMP, is a senior technical director at PSC Biotech and has more than 20 years of experience in pharmaceutical microbiology, environmental monitoring, and quality assurance. She obtained her master’s degree in microbiology from North Carolina State University. Booth is author of Method Development and Validation for the Pharmaceutical Microbiologist. During her career, she has worked in microbiology, consulting, quality assurance, CDMOs, R&D, and quality control laboratories. She has developed and validated numerous microbial methods and has worked with many different product types. She also performs cGXP audits, risk assessments, and gap assessments. Booth is author of the Institute of Validation Technology (IVT) peer-reviewed articles “Harmonized Microbial Limits Testing Validation Strategies” and “Antimicrobial Effectiveness Testing Validation Strategies.”