Analysis of standards and classification of cleanliness levels of microbiological laboratories (clean rooms)!
2026-04-10
A microbiology laboratory usually consists of three areas: clean area, work area and sterile area, which can be divided into several rooms such as preparation room, culture room, microorganism storage room, disinfection room and sterile room. Depending on the area of specialization (environmental science, food processing, pharmaceuticals, medicine, etc.) and the nature of the activity (teaching, manufacturing, research, testing, etc.), the composition and scale of microbiology laboratories can vary significantly.
In terms of the general environment, the air in cleanrooms such as microbiology laboratories and cleanrooms is dominated by bacteria with a diameter of 0.5–5 μm and molds with a diameter of 2–30 μm, which adhere to dust in the air, forming biological particles of a certain size that remain suspended in the air, which directly affects the air environment of the microbiology laboratory.
When planning, designing and constructing microbiology laboratories, air cleanliness is a key factor. Currently, the following main standards and documents regarding cleanrooms and cleanliness classification are in force in China:
(1) GB 50073-2013 “Cleanroom Design Standards”.
(2) GB/T25915.1-2010 “Clean rooms and associated controlled environments. Part 1: Air purity classes."
(3) GB 50687-2011 “Technical standards for the construction of clean rooms for the food industry.”
(4) GB 50472-2008 "Cleanroom design standards for the electronics industry."
(5) GB 50457-2008 “Clean room design standards for the pharmaceutical industry”.
(6) YY 0033-2000 “Management standards for the production of sterile medical devices.”
(7) Appendix 1 to the “Quality Management Standards for the Production of Medicines (Revision 2010)”.
(8) “Rules of application and standards for verification and evaluation of quality management standards for the production of medical devices in relation to sterile medical devices (in trial mode).”
In industries such as pharmaceuticals, electronics and food processing, the situation is simpler because there are appropriate standards for them. But what should other industries do? Some suggest immediately choosing the GB 50073-2013 standard, but, in our opinion, this is not entirely true.
The GB 50073-2013 standard specifies requirements only for suspended particles, but does not contain provisions for microbiological indicators, which are of greatest importance for sterile laboratories. If your laboratory only needs to control suspended particles, then GB 50073-2013 will fully satisfy the requirements. And if there are requirements for monitoring microbiological indicators, how then should you choose?
Let's first look at the main cleanliness classifications given in the above standards and documents: The GB 50073-2013 and GB/T 25915.1-2010 standards, which use the ISO classification, define the following cleanroom air cleanliness levels:
Note: GB 50472-2008 refers to the classification of GB 50073-2013 and does not contain its own classification provisions.
GB 50457-2008 "Cleanroom Design Standards for the Pharmaceutical Industry" establishes the following levels of cleanliness:
Note: The requirements of GB 50457-2008 are a direct reference to GMP 1998, and the requirements of YY 0033-2000 “Manufacturing Management Standards for Sterile Medical Devices” and “Rules for Application and Standards for Testing and Evaluation of Medical Device Manufacturing Quality Standards for Sterile Medical Devices (Trial Mode)” are equivalent.
The Quality Management Standards for Pharmaceutical Manufacturing (2010 Revision) establishes the following requirements for cleanliness levels in sterile operations:
Airborne Particle Standards for All Levels of Cleanrooms
Dynamic Standards for Microbiological Monitoring of Cleanrooms
Note: The classification of purity levels in GMP (2010) has been revised to reflect EU GMP requirements.
The GB 50687-2011 classification is basically the same as the GMP (2010) standard, except that the class names are changed to I, II, III, IV, and the GMP (2010) requirements are more stringent. In accordance with GMP (2010), only dynamic monitoring of airborne and sediment microorganisms is carried out, while the GB 50687-2011 standard provides for both static and dynamic monitoring.
So what standard should you focus on when designing and building a microbiology laboratory? This depends on the specific area of specialization and the risks associated with analyzing different samples. Don't choose blindly—let's compare these standards first.
(1) Based on the classes established in GB 50073-2013 and GB/T 25915.1-2010, i.e. ISO classification, suspended particle sizes are used as the limit value.
(2) GMP Class A (2010) corresponds to ISO Class 4.8; Class 4.8 is calculated using a formula using a suspended particle size limit of ≥5.0 µm.
(3) GMP (2010) Class B, GB 50687-2011 Class I (static) and GB 50478-2008 Class 100 correspond to ISO Class 5, which is what we usually call Class 100.
(4) Level I (dynamic) of GB 50687-2011 corresponds to ISO level 6, which is what we usually call level 1000.
(5) Class C (static) according to GMP (2010), class II (static) according to GB 50687-2011 and class 10000 according to GB 50478-2008 correspond to ISO class 7, that is, what we usually call class 10000.
(6) GMP (2010) Level C (Dynamic)/Level D, GB 50687-2011 Level II (Dynamic)/Level III (Static) and GB 50478-2008 Level 100000 correspond to ISO Level 8, which is what we commonly call Level 100000.
(7) Class IV of GB 50687-2011 corresponds to Class 9 of ISO.
Thus, since the ISO standards set requirements only for suspended particles, but do not contain restrictions regarding microbiological indicators, we recommend: for cleanrooms that are not subject to microbiological indicators restrictions, you can focus on the requirements of the GB 50073-2013 or GB/T 25915.1-2010 standards; in the food, electronics and pharmaceutical industries, relevant industry standards should be followed; and microbiological laboratories in other areas are recommended to follow the relevant GMP requirements (2010).
At the same time, the risk associated with the test samples should be taken into account when determining the level of cleanliness of the microbiology laboratory.
