Medical Device Purification Workshop Decoration And Purification Project

Medical device purification workshop decoration and purification project

How to define purification levels

The quality of the products in the medical device purification workshop is directly determined by its cleanliness standards. According to GMP specifications, the concentration of microorganisms per cubic meter in the workshop air must be controlled at an extremely low level. This is specifically reflected in the fact that the number of floating bacteria per cubic meter is no more than 10, and the number of sedimentation bacteria per dish is no more than 3. In terms of dust particles, the number of particles above 0.5 microns per cubic meter must not exceed 35,200. These data are not just empty talk. In 2025, a medical device factory in Suzhou had a batch of surgical instruments recalled due to excessive particulates in the workshop, causing a loss of more than 2 million yuan. Companies have to determine the purification level according to the type of product. For implantable devices, the requirement is level 100, while for in vitro diagnostics, level 10,000 is enough.

How to design ventilation system

The core means to eliminate pollution is purification workshop ventilation. In order to ensure the ventilation effect, the air needs to pass through a high-efficiency filter (HEPA). The filtration efficiency of this filter for 0.3 micron particles can reach 99.97%. In addition, the air supply volume must meet the requirement of air changes per hour. Specifically, a 100-level workshop needs to have at least 25 air changes, and a 10,000-level workshop must have a minimum of 15 times. There is a purification engineering company in Beijing. They once installed a dual-fan system for an orthopedic equipment factory. The backup fan in this system can automatically start within 30 seconds to avoid various risks caused by shutdown. To ensure that the ventilation duct does not produce particles, it must be made of stainless steel, otherwise the pipe will be easy to rust. The wind speed of the air outlet must be measured every period. This requires the use of an air volume hood and a test every quarter to ensure that the wind speed is maintained at 0.3 – 0.5 meters/second. Otherwise, microorganisms can easily accumulate in the workshop.

How to choose materials for stainless steel equipment

The tooling equipment in the workshop must be made of stainless steel, with 304 or 316L being the preferred material. 304 stainless steel has strong corrosion resistance and is suitable for routine cleaning. 316L has added molybdenum element, which can resist chloride ions in the cleaner. The thickness of the work surface should be no less than 1.5 mm, and it can bear a load of 200 kg without deformation. In 2024, a purification workshop in Shenzhen used 1.2 mm stainless steel shelves. After half a year, rust spots appeared. After cleaning, there were still residues, so they were all replaced in the end. The welded parts must be passivated to eliminate weld spots, otherwise they will become a hiding place for microorganisms. When riveting, use argon arc welding, and the weld bead must be even and free of pores.

How to keep materials clean

The riveting and welding process of stainless steel will have a direct impact on the cleanliness. Before welding, the surface oil must be removed and wiped with acetone to avoid the appearance of carbides after welding. During the welding process, 99.99% high-purity argon gas must be used for protection in order to prevent oxidation. Pickling and passivation must be carried out after welding to form a protective film. Just like a workshop in Zhejiang in 2023, due to no passivation during welding, This resulted in rust on the surface of the stainless steel, and eventually the cleanliness dropped from level 100 to level 10,000. The riveted areas needed to be polished to a roughness of Ra ≤ 0.8 microns to prevent particles from adhering. Before entering the site, all materials must be blow-dried in the buffer area and wiped with a dust-free cloth to confirm that there is no dust before entering the core area.

How to control personnel operations

The people involved are the main source of pollution, and training is the key. Before entering the workshop, you must change into special clean clothes. This clean clothes include coveralls, masks, gloves and shoe covers. Use unscented soap when washing your hands, rub for at least 20 seconds, and then enter the air shower for 15 seconds. In 2025, an employee of an equipment company in Shanghai failed to change his shoes as required and brought in outdoor dust, resulting in a 12% drop in the pass rate of the product that day. Movements in the workshop should be gentle and gentle to reduce the shedding of skin flakes. The maximum number of personnel in each shift must be controlled within 8 people. The plate sampling method should be used regularly to detect bacterial colonies on employees' hands. If the bacteria exceed the standard, relevant personnel need to be retrained.

How to perform cleaning and disinfection

In daily management, the cleaning process must be solidified. Use 75% ethanol to wipe the stainless steel surface every day, and soak the tools in quaternary ammonium salt disinfectant for 30 minutes every week. In 2024, a purification workshop in Wuhan switched to chlorine-containing preparations due to improper selection of disinfectants, resulting in pitting corrosion of stainless steel. The repair cost 150,000 yuan. The correct approach is to use a neutral detergent to remove stains, then spray disinfectant, and finally rinse with sterile water. Dust particle count monitoring is carried out once a month, and the air is tested with a planktonic bacteria sampler every quarter. Beijing Huaxu Purification Engineering Company provides full third-party testing services and makes rectifications within 48 hours after the report is issued. Which link do you think is most likely to be missed in the cleaning steps in your own workshop? Communicate and discuss in the comment area, like and save it to prevent it from getting lost.