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Sterile Clean Room

Sterile Clean Room for Medical Devices

Building code for a sterile clean room for production of medical devices as below:


1. International standard ISO/DIS 14644


2. Code for design of clean room workshop GB50073-2001


3. GMP-97 specification for clean room workshop of medical equipment packaging workshop


4. Good manufacturing practice GMP-98


5. Code for construction and collection of clean room JGJ 71-90


6. Code for construction and acceptance of ventilation and air conditioning engineering GB 50243-2002


7. Federal standard fs209e-92


According to the requirements of relevant specifications, clean rooms complying with relevant standards are required for sterile clean room for medical device production, phamacy production, medical biology laboratory, operating room, etc. The final completion acceptance for a sterile clean room cannot be relied on the construction, but must be strictly checked from the design and equipment selection stage. During the whole process of construction, the main key points must be strictly inspected and supervised, and regular monitoring in actual use to ensure that the sterile clean room can meet the design index and use requirements.


Aseptic medical devices are any medical devices marked as "aseptic". The production of clean room is the basic condition to ensure the quality of aseptic medical devices. It is necessary to control the environment during the production process of aseptic medical devices and regulate their production, so as to prevent the environment from polluting the aseptic medical devices. The sterile clean room must meet the requirements of specified environmental parameters for construction and regular monitoring.


The following problems should be considered in the construction of medical device sterile clean room project:


1. Purification materials required;


2. Design, installation, commissioning, maintenance and other comprehensive services for the clean room project;


3. Air conditioning purification part of clean room project;


In the dynamic monitoring of sterile clean rooms, the main reasons for the change of the pressure difference between clean rooms are the flow of people, the insufficient fresh air volume and the frequent opening of doors. If the static pressure difference between clean rooms and the atmosphere or between clean rooms of different levels is in a critical state, it is likely that the pressure difference cannot meet the requirements due to the flow of people and the insufficient supply of fresh air during the dynamic detection.


  • Suspended particles, floating bacteria and settling bacteria


If the test conditions fail to meet the requirements of specified environmental parameters (temperature and humidity, wind speed, air change times, static pressure difference within the specified range), the test results of suspended particles, floating bacteria or settling bacteria shall be regarded as invalid. As temperature, relative humidity, wind speed, air change times and static pressure difference constitute the microclimate of the clean room, which is an important indicator of whether the sterile clean room is maintained normally or not. In order to ensure the scientificity and accuracy of the performance monitoring data of the sterile clean room, the testing department should test the temperature, relative humidity, air change times, static pressure difference and other preconditions at the same time when testing the suspended particles and microorganisms.


The test standards of the sterile clean room design of pharmaceutical clean room and sterile medical equipment in terms of temperature, relative humidity, wind speed, air change times and static pressure difference are all implemented in accordance with the code for design of clean workshop. The problems in the design of clean room of pharmaceutical factory also have reference value for sterile medical equipment clean room.


  • Temperature


The reason why the room temperature of the sterile clean room exceeds the design range in summer is mostly because the air conditioning air supply volume of each clean room, i.e. the air change frequency, which was determined at the beginning, only focused on meeting the cleanliness index, and ignored the check calculation of the heat balance of each clean room. Therefore, in the process of design and operation of the production clean room, it is necessary to modify the parameters of air conditioning and air supply in the clean room in real time to ensure that the temperature of the production clean room is maintained at 18-28 C in each season. Temperature and relative humidity mainly affect the production process and bacterial reproduction conditions, and also cause the impact of the comfort of production operators on product quality.


  • Air supply volume and air change times


In the design stage of medical equipment sterile clean room, the determination of air supply volume should first meet the requirements of air change times of corresponding cleanliness level, and at the same time, the air volume should be further determined through heat and humidity load verification, on the basis of which the high-efficiency filter should be selected. The treatment air volume of the filter shall be less than or equal to the rated air volume, and the resistance and efficiency of the high-efficiency (sub high efficiency and super high efficiency) air filter set in the same clean area shall be close.


Generally, the air supply volume of the sterile clean room shall be the maximum value of the following three items:

  • the air supply volume to ensure the air cleanliness level; the air supply volume calculated according to the heat and humidity load;

  • and the fresh air volume supplied to the sterile clean room. The fresh air volume shall take the maximum value of the following two items: the sum of the fresh air volume required to compensate the indoor exhaust air volume and maintain the indoor positive pressure value;

  • ensure that the fresh air volume supplied to each person in the clean room per hour is not less than 40m3.


For a specific sterile clean room project, the air change frequency should be determined according to the actual situation. In particular, the cleaning requirements are low, sometimes the number of air changes depends on the indoor heat. Generally, a ventilation frequency is calculated according to the dust emission of indoor staff and equipment (or the dust emission of staff multiplied by a factor), whichever is larger. Sometimes, for the sake of safety, the ventilation frequency can be calculated by multiplying by a service factor.


Dust particles, suspended particles and microorganisms mainly affect product quality and cause cross infection. 80% - 90% of the dust and bacteria in the clean room come from outdoor air, and 80% - 90% of them come from people in other factors, such as people and enclosure structure. It can be seen that in addition to the dust and bacteria brought by the outdoor air, personnel are the main reason for dust particles in the sterile clean room. The test data show that the movement range and the speed of walking are different.


The operation of the sterile clean room operator should be gentle and stable, and unnecessary actions should be avoided as much as possible, especially the movements of legs such as fast walking, so as to reduce the dust production in the sterile clean room. Due to different materials and styles, there are great differences in dust production. The first choice should be one-piece, dense nylon thick clean clothes, which produce less dust than other kinds of clean clothes. The design of sterile clean room adopts epoxy resin self-leveling coating on the ground and metal sandwich panel wall, which produces less dust than other building materials.


Therefore, from two aspects of personnel control and plant design, the number of dust particles in the sterile clean room can be reduced.


In addition to controlling pollution sources and reducing the amount of pollution to prevent particulate pollution in the clean room, air purification treatment methods such as controlling the pressure in the room can effectively prevent outdoor pollution from invading the room or preventing indoor pollution from escaping out of the room. The reasonable air distribution can effectively eliminate the indoor pollution. These ways are all related to the air volume (wind speed) or air change times of the purification system. Clean room is a complex with requirements for air change times, static pressure difference, temperature, humidity, illumination, etc.


The design, construction, monitoring and management of sterile clean rooms are equally important. The clean room construction of sterile medical devices should start from the design, and the clean room monitoring involves the enterprise's own management procedures and personnel operation training. Before the sterile clean room is put into operation, comprehensive performance verification shall be carried out, including design before construction, project preparation, monitoring of construction period, static monitoring after completion, dynamic monitoring of actual production process, etc. The clean room manufacturer should establish a set of scientific and effective clean room management system and procedures, and record and analyze and solve the existing problems in time.


Code for the design of clean workshop in pharmaceutical industry (GB50457-2008) was issued in November 2008 and implemented on June 1, 2009. It is another national standard following the code for the design of sterile clean room workshop (GB 50073-2001) and will provide guidance for the design of clean workshop in pharmaceutical industry. With the introduction of operable standards, monitoring the clean room will become an important guarantee of clean production environment.


With the rapid development of clean room construction, sterile medical equipment production plays an important role in improving product quality. Product quality is not the last detected but produced by strict process control. Environmental control is the key link of production process control. It is very important to do a good job of clean room monitoring for product quality. At present, the monitoring of clean room in medical equipment manufacturing enterprises is not popular, and the importance of clean room is not well understood. How to correctly understand and implement the current standards, how to carry out a more scientific and reasonable evaluation of the clean plant, how to put forward a reasonable test index for the operation and maintenance of the clean plant are the common concerns of the enterprise and the monitoring and supervision personnel.


Attention to clean room construction of medical devices:


  • Site selection requirements


1. When selecting the plant site, it should be considered that the natural environment and sanitary conditions around the site are good, at least there is no source of air or water pollution, and it should be far away from the main roads, freight yards, etc.


2. Environmental requirements of the plant area: the ground and road of the plant area shall be flat and free from dust. It is advisable to reduce the exposed area or take measures to control dust through greening. Garbage, idle articles, etc. shall not be stored in the open air. In short, the environment of the plant shall not cause pollution to the production of sterile medical devices.


3. The overall layout of the plant area shall be reasonable: it shall not have adverse effects on the production area of sterile medical devices, especially the clean area.


  • Layout requirements of clean room (area)


The level of cleanliness shall be set in accordance with the guidance for setting the level of cleanliness in the production environment of sterile medical devices in Appendix B of the code for production management of sterile medical devices. Pay attention to the following aspects in the design of clean room (area):


1. Arrange according to the production process. The process shall be as short as possible to reduce cross and back, and the flow of people and logistics shall be reasonable. The personnel purification room (coat room, washroom, clean work clothes room and buffer room), material purification room (unpacking room, buffer room and double-layer transfer window) must be equipped. In addition to the use room required by the product process, the cleaning room, laundry room, temporary storage room, tool cleaning room, etc. shall also be equipped. Each use room is independent of each other. The area of the cleaning workshop shall ensure the basic requirements Under the premise of seeking, it is suitable for the production scale.


2. According to the level of air cleanliness, it can be written in the direction of people flow, from low to high; the workshop is from inside to outside, from high to low.


3. No cross contamination in the same clean room (area) or between adjacent clean rooms (areas):


1) Production process and raw materials will not have mutual influence on product quality;


2) There are airlocks or anti-pollution measures between clean rooms (areas) of different levels, and materials are transported through passbox. 


4. Air purification shall meet the requirements of Chapter IX of GB 50457-2008 code for design of clean workshop in pharmaceutical industry. The fresh air volume in the clean room shall take the following maximum values:


1) Compensation of indoor exhaust air volume and fresh air volume required to maintain indoor positive pressure;


2) Indoor fresh air shall not be less than 40m ³ / h.


5. The per capita area of the sterile clean room shall not be less than 4 ┫ (except for corridor, equipment and other items), so as to ensure a safe operation area.


6. If it is an in vitro diagnostic reagent, it shall meet the requirements of detailed rules for the production and implementation of in vitro diagnostic reagent (Trial). The treatment of negative and positive serum, plasmids or blood products shall be carried out under the environment of at least ten thousand levels, with relative negative pressure with adjacent areas or keep in line with the protection requirements.


7. The direction of return air, supply air and water making pipeline shall be indicated.

sandwich panel
clean room door
clean room window
clean room alum.
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