Between rooms of different cleanliness grades, it is required to establish apressure cascadeto preventcross contamination. Annex 1 of the EU GMP Guide requires a pressure difference of at least 10 Pascal between two different cleanliness classes. These pressures can be achieved if the structure (walls, ceiling, windows and doors) is tight. The pressure level is usually controlled in such a way that the supply air is kept constant, and the exhaust air is controlled via volume flow controllers to maintain the corresponding pressure difference. The pressure differences in a manufacturing area for sterile pharmaceuticals must be continuously measured and recorded. If a pressure drop occurs, an alarm must be triggered. This also applies to the airlocks.
不同洁净度等级的房间之间，要求建立压力梯级，防止交叉污染。欧盟GMP指南附录1要求两个不同清洁度等级之间的压差至少为10帕斯卡。如果结构(墙壁、天花板、窗户和门)紧密，这些压力就可以实现。通常控制压力水平的方式是使送风保持恒定，而通过容积流量控制器控制排风以保持相应的压差。无菌药品生产区域的压力差必须连续测量和记录。如果出现压降，必须触发告警。这也适用于气闸。
与压差相关的文章见：为什么不同级别洁净室的压差标准为不低于10帕？（
为什么不同级别洁净室的压差标准为不低于10帕？）
为什么不同级别洁净室的压差标准为不低于10帕？）与气闸相关的文章见：对气锁间的GMP要求是什么？（对气锁间的GMP要求是什么？）
对气锁间的GMP要求是什么？）One can generally differentiate between two differenttypesof pressure cascade systems:
通常可以分为两种不同类型的压力级联系统:
“bubble type” i.e. positive pressure system and
“气泡式”即正压系统
“sink type” i.e. negative pressure system
“下沉式”即负压系统
Thebubble type systemfocuses on protecting the product from contamination from adjacent areas of lower cleanliness and from the employee. This is achieved by maintaining a higher static pressure in the clean rooms or clean room area than in the adjacent areas. Alternatively, the flow at leak points can be adjusted so that there is a flow from the clean area to the less clean area. These measures ensure that contaminations in the air always flow towards the less clean area. This prevents the ingress of contaminants from areas of low purity. The bubble type system is often used in the manufacture of liquid products. They are generally more susceptible to microbiological contamination.
气泡式系统的重点是保护产品免受邻近低洁净度区域和员工的污染。这是通过在洁净室或洁净室区域保持比相邻区域更高的静压来实现的。或者，可以调整泄漏点处的流量，使其从洁净区流向较不洁净区。这些措施确保空气中的污染物总是流向不太干净的区域。这可以防止污染物从低级洁净区进入。气泡式系统常用于生产液体产品。它们通常更容易受到微生物污染。
Sink type systemsare used where, in addition to protecting the product, it is important to protect the personnel and the environment. This is the case, for example, with highly active pharmaceutical ingredients (HAPI, high potent APIs) or radioactive substances. To prevent contaminated air from reaching adjacent areas, a negative pressure is created in the hazard zone relative to the surroundings/adjacent areas. This system is often used where dusty substances or products are processed.
下沉式系统用于除保护产品外，在保护人员和环境方面也起到很重要的作用。例如，高活性药物成分(HAPI，高效原料药)或放射性物质就是这种情况。为了防止受污染的空气到达邻近区域，在危险区相对于周围环境/邻近区域产生负压。该系统通常用于处理含尘物质或产品的地方。
To select the correct pressure system for the intended production, first the following steps are required:
要为预期的生产活动选择正确的压力系统，首先需要以下步骤:
Analyze the entire production process and document all process steps required to determine the clean room grades.
分析整个生产工艺，并记录所有工艺步骤，以确定洁净室等级。
Perform a risk analysis:
进行风险分析:
What is the primary need for protection (product, personnel, environment)?
保护(产品、人员、环境)的首要需求是什么?
What are the contamination risks (particles, microbiology, endotoxins/pyrogens, chemicals)?
什么是污染风险(颗粒、微生物、内毒素/热原、化学品)?
What are sources of contamination for the product?
产品的污染源是什么?
Where is the greatest risk of contamination?
哪里最容易被污染?
Define the pressure levels for each area (airlocks, clean room, etc.)
定义每个区域(气闸、洁净室等)的压力等级。
Documentation should be carried out as part of the Contamination Control Strategy mentioned above.
文件应作为上述污染控制策略的一部分进行。
更多污染控制策略相关的文章见：
污染源：房间和设施
细胞和基因治疗设施的污染控制策略
检查员眼中的污染控制策略（CCS）
如何创建污染控制策略（CCS）？
检查员眼中的欧盟GMP指南附录1的实施现状
新版EU GMP指南附录1对A级和B级5µm粒子的要求
洁净室的自净时间与恢复时间
The planning of a coherentcleanliness zone conceptis a challenging task. To avoid errors, the following aspects in particular should be taken into account, which unfortunately are often forgotten during planning.
规划一个连贯的清洁区域是一项具有挑战性的任务。为了避免错误，应该特别考虑以下几个方面，不幸的是，这些方面在规划过程中经常被遗忘。
Separate airlocks for incoming and outgoing materials and/or waste and product if there is a risk of re-contamination
如果有再污染的风险，对进出物料和/或废物和产品设置单独的气闸
Sufficient area for material transfer
有足够的空间进行物料转移
A Sufficient storage space even in classified areas – airlocks are not a storage area
即使在洁净区也有足够的存储空间-气闸不是存储区域
Separation of material with different status in the storage areas
将不同状态的物料在存储区域进行隔离
Separation of washing and process rooms – washing machines and sterilizers for pass-through operation are ideal
清洗室和工艺室的分离-用于直通操作的洗衣机和灭菌器是理想的
Decontamination procedures must be followed when material is brought in
当物料被带入时，必须遵循去污染程序
Access controls for all areas
所有区域的访问控制
原文来自GMP-VERLAG PEITHER AG网站，略有删减，点击“阅读原文”可以查看原文。
