Pressure differential control requirements for clean rooms in pharmaceutical industry

Pressure differential control requirements for clean rooms in pharmaceutical industry
In the Chinese standard, the aerostatic pressure difference between the medical clean room (area) with different air cleanliness levels and between the medical clean room (area) and the non-clean room (area) should not be less than 5Pa, and the static pressure difference between the medical clean room (area) and the outdoor atmosphere should not be less than 10Pa.
Eu GMP recommends that the pressure difference between adjacent rooms at different levels of the pharmaceutical industry clean room should be maintained between 10 to 15Pa. According to the WHO, a pressure difference of 15Pa is usually used between adjacent areas, and the generally acceptable pressure difference is 5 to 20Pa. China’s 2010 revised GMP requires that “the pressure difference between clean and unclean areas and between different levels of clean areas should not be less than 10 Pa.” Where necessary, appropriate differential pressure gradients should also be maintained between different functional areas (operating rooms) of the same cleanliness level.”
WHO points out that airflow reversal occurs when the design pressure difference is too low and the pressure difference control accuracy is low. For example, when the design pressure difference between two adjacent clean rooms is 5Pa, and the pressure difference control accuracy is ±3Pa, the airflow reversal will occur in extreme cases.
From the perspective of drug production safety and prevention of cross-contamination, the pressure difference control requirements of the pharmaceutical industry clean room are higher, therefore, in the design process of the pharmaceutical industry clean room, the design pressure difference of 10 ~ 15Pa is recommended between different levels. This recommended value is in line with the requirements of China GMP, EU GMP, etc., and is being adopted more and more widely.