Medical Device Purification Engineering - Design Specification for Aseptic Cleanroom Engineering Reference:

1. International standard ISO/DIS 14644

2. Design Code for Cleanroom and Factory Buildings GB50073-2001

3. Medical Device Packaging Workshop Cleanroom Building Specification GMP-97

4. Good Manufacturing Practice for Drugs (GMP-98)

5. Clean room construction and difficult to receive specifications JGJ 71-90

6. Code for Construction and Acceptance of Ventilation and Air Conditioning Engineering (GB 50243-2002)

7. US Federal Standard FS209E-92

According to relevant regulations, clean rooms that meet relevant standards are required to be built in sterile medical device production workshops, drug production workshops, medical biology laboratories, operating rooms, etc. When constructing or renovating a clean room, it is not necessary to rely on the final completion acceptance to ensure the quality of the clean room. Strict control must be carried out from the design and equipment selection stage, and the main key points must be strictly inspected and supervised throughout the construction process. Regular monitoring during actual use is necessary to ensure that the clean room meets the design specifications and usage requirements. Aseptic medical devices are any medical devices labeled as "sterile". The production clean room is the basic condition for ensuring the quality of sterile medical devices. The environment for controlling the production process of sterile medical devices and regulating their production to prevent environmental pollution of sterile medical devices. The clean room must meet the requirements of the specified environmental parameters for construction and regular monitoring.

In the construction of medical device purification engineering, the following issues need to be considered:

1. Purification materials required for clean room engineering in medical device packaging workshop;

2. Comprehensive services including design, installation, commissioning, and maintenance of clean rooms in medical device factories and packaging workshops;

3. Medical device packaging workshop clean room engineering air conditioning purification part

Temperature and relative humidity

When there are no special regulations, sterile medical devices usually require a temperature of 18-28 ° C according to regulatory standards and testing, and a humidity of 45%~65%. Enterprises can generally control it within the requirements. If it is found during dynamic monitoring that the requirements are not met, it may be due to the presence of high heat generating instruments and equipment indoors.

Airflow, air exchange rate, static pressure difference

When the volume of the clean room is determined, the number of air changes is determined by the supply air volume of the room, while the static pressure difference depends on the difference between the supply air volume, return air volume, and exhaust air volume of the room. The total supply air volume, fresh air volume, total exhaust air volume, and external pressure difference of the system can be achieved by adjusting the frequency and speed of the fan or the opening degree of the main valve. The air volume and pressure of each room can be achieved by adjusting the opening degree of the branch pipeline valves.

During the actual testing process, it was found that when adjusting the air supply volume of a clean room with an unqualified ventilation rate by adjusting the branch air valve, it often causes changes in the air supply volume of other clean rooms in the same clean area, which disrupts the air distribution of the entire clean area and makes the problem more complex. In addition, it is common to encounter situations where the ventilation rate is qualified but the pressure difference is unqualified, which is more common in the second scenario. The main reason is the poor airtightness of the protective structure and the difficulty in adjusting the return air grille.

In the dynamic monitoring of clean rooms, personnel flow, insufficient fresh air volume, and frequent opening of doors are the main reasons for the pressure difference changes between each clean room. If the static pressure difference between the clean room and the atmosphere or between different levels of clean rooms is in a critical state, dynamic detection is likely to result in insufficient fresh air volume due to personnel flow, causing the pressure difference to not meet the requirements.

Suspended particles, planktonic bacteria, and settling bacteria

If the testing conditions cannot meet the specified environmental parameters (temperature and humidity, wind speed, air exchange rate, static pressure difference within the specified range), the test results of key items such as suspended particles, planktonic bacteria, or settling bacteria should be considered invalid. Due to the fact that temperature, relative humidity, wind speed, air exchange rate, and static pressure difference together constitute the microclimate of the clean room, they are important indicators for the normal maintenance of the clean room. Therefore, the testing of key processes and key items can be revised to the full performance testing of key processes. Only in this way can the production clean room be comprehensively and systematically monitored. To ensure the scientific and accurate data monitoring of clean room performance, the testing department should conduct temperature, relative humidity, air exchange rate, static pressure difference and other prerequisite tests simultaneously when conducting key suspended particle and microbial tests.

The testing standards for temperature, relative humidity, wind speed, air exchange rate, and static pressure difference in the design of pharmaceutical cleanrooms and sterile medical equipment cleanrooms are all implemented in accordance with the "Design Specification for Cleanrooms". The design problems of pharmaceutical cleanrooms also have reference value for sterile medical equipment cleanrooms.

Temperature

The reason why the room temperature in clean rooms exceeds the design range in summer is often due to the initial determination of the air supply volume and air exchange rate of each clean room, which only focuses on meeting the cleanliness index and neglects the verification calculation of the thermal balance of each clean room. Therefore, in the design and operation of the production clean room, it is necessary to make real-time adjustments to the air conditioning supply parameters of the clean room to ensure that the temperature of the production clean room is maintained at 18-28 ° C in all seasons. Temperature and relative humidity mainly affect the product production process and bacterial growth conditions, and can also cause the impact of the comfort level of production operators on product quality.

Air supply volume and air exchange rate

In the design phase of medical device purification engineering sterile clean room engineering, the determination of air supply volume must first meet the ventilation requirements of the corresponding cleanliness level, and further determine the air volume through heat and moisture load verification. Based on this, high-efficiency filters are selected. The processing air volume of the filter should be less than or equal to the rated air volume, and the resistance and efficiency of high-efficiency (sub high efficiency, super high efficiency) air filters set in the same clean area should be close.

The air supply volume for a clean room should be the maximum of the following three values: the air supply volume required to ensure the cleanliness level of the air; Determine the air supply volume based on the calculation of heat and humidity loads; The amount of fresh air supplied to the cleanroom. The fresh air volume should take the maximum of the following two values: the sum of the fresh air volume required to compensate for indoor exhaust volume and maintain positive indoor pressure; Ensure that the fresh air supply per person per hour in the clean room is not less than 40m3.

For a specific cleanroom project, the air exchange rate should be determined based on the actual situation. Especially for those with lower cleanliness requirements, sometimes the air exchange rate depends on the indoor heat dissipation. Generally, a ventilation rate is calculated based on the dust generation of indoor staff and equipment (or the dust generation of staff multiplied by a coefficient), and the larger of the two is sufficient. Sometimes, for safety reasons, a usage coefficient can be multiplied to calculate the ventilation rate.

Dust particles, suspended particles, and microorganisms mainly affect product quality and cause cross infection. 80% to 90% of the dust and bacteria in clean rooms come from outdoor air, while in other factors such as people and building structures, 80% to 90% come from people. It can be seen that besides the dust and bacteria brought by outdoor air, personnel are the main cause of dust particles in clean rooms. The test data shows that the amplitude of personnel movements and the speed of walking produce different amounts of dust.

The movements of clean room operators should be gentle and steady, and unnecessary movements should be avoided as much as possible, especially lower limb movements such as rapid walking, in order to reduce the amount of dust produced in the clean room. The amount of dust produced varies greatly depending on the material and style of the clean clothing chosen. The preferred choice is a one-piece, dense nylon thick clean suit, which produces less dust than other types of clean suits. The clean room design uses epoxy resin self leveling coating on the floor and metal color steel wall panels, which generate less dust than using other building materials.

Therefore, considering both personnel control and factory design, the number of dust particles in the clean room can be reduced. In addition to controlling pollution sources and reducing the amount of pollution to prevent particle pollution in clean rooms, methods of air purification treatment such as controlling indoor pressure can effectively prevent outdoor pollution from entering the room or prevent indoor pollution from escaping outdoors. And use reasonable airflow organization to effectively eliminate indoor pollution. These methods are all related to the air volume (wind speed) or air exchange rate of the purification system. A clean room is a complex that has requirements for air exchange rate, static pressure difference, temperature, humidity, illumination, etc.

The design, construction, monitoring, and management of clean rooms are equally important. The construction of a clean room for sterile medical devices should start with design, and clean room monitoring involves the company's own management regulations and personnel training. Before the cleanroom is put into operation, comprehensive performance verification should be carried out, including design before construction, engineering preparation, monitoring of the construction period, static monitoring after completion, and dynamic monitoring of the actual production process. Enterprises should establish a scientific and effective clean room management system and regulations, and promptly record and analyze any problems that arise during management.

The Design Code for Cleanrooms in the Pharmaceutical Industry (GB50457-2008) was released in November 2008 and implemented on June 1, 2009. This is another national standard following the Design Code for Cleanrooms (GB 50073-2001), which will provide guidance for the design of pharmaceutical cleanrooms. With the introduction of operational standards, monitoring clean rooms will become an important guarantee for a clean production environment.

The rapid development of clean rooms for sterile medical device production plays an important role in improving product quality. Product quality is not determined by final testing, but by strict process control during production. Environmental control is a key link in production process control, and monitoring the cleanroom is crucial for product quality. At present, the monitoring of clean rooms in medical device manufacturing enterprises is not yet widespread, and enterprises have insufficient awareness of its importance. How to correctly understand and implement current standards, how to conduct more scientific and reasonable evaluations of clean rooms, and how to propose reasonable testing indicators for the operation and maintenance of clean rooms are common concerns for enterprises and monitoring and regulatory personnel.