CIP is the abbreviation for Clean-In-Place, SIP for Sterilize-In-Place. In both CIP and SIP, the cleaning and sterilization of devices and systems take place without their disassembly being necessary, directly on-site or "in place." No disassembly of individual components, the entire container, or even the complete system occurs. This saves time, labor, and thus money, because the method reduces personnel costs and minimizes downtime. All of this offers the company a significant advantage. Both processes complement each other and are usually used one after the other.
These are the biggest advantages of both methods:
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Maintenance of product safety
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Reduction of downtimes
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Increase in system efficiency
For which industries are these processes suitable?
The systems are primarily used in areas where hygiene is essential, such as the pharmaceutical, cosmetic, beverage, and food industries. The processes are primarily relevant in the production of liquid and partly semi-solid dosage forms. In short: Wherever organic material can accumulate and decompose and there is a danger of pathogenic bacteria and other microorganisms forming, CIP and SIP are successfully in use.
The automated in-place processes enable thorough and rapid cleaning and sterilization even with constantly changing production processes and frequent cleaning intervals, especially of pipes and tank systems. In combination, the two systems increase efficiency and safety for the consumer by reliably removing residues and subsequently eliminating potentially harmful germs.
What are the differences between CIP and SIP?
The commonality of the two methods is the application to internal surfaces in a closed system. Both processes are based on the same principle and ultimately build on each other, but each serves a different purpose. CIP cleaning always takes place first, because any existing residues can hinder the effect of the steam and thus impair reliable and safe germ control.
The procedure in many operations is as follows:
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Pre-rinsing with water
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Cleaning with a lye (alkaline solution)
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Rinsing out the lye with water
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Cleaning with an acid
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Rinsing out the acid with water
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Thermally sterilizing the system with pure steam.
The process ends after sterilization, as a subsequent rinse leads to recontamination of the system unless germ-free WFI water is used. Usually, however, sterilization is the last step before production. Rinsing with water is part of the CIP conclusion and takes place before SIP. After SIP, often only drying with sterile air occurs.
What happens during the CIP method?
The Clean- or Cleaning-In-Place process, as already mentioned, takes over the cleaning of the entire container or system without the disassembly of individual components. Today, this is mostly a fully automatic process that precisely adheres to fixed times and specified parameters. The individual work steps are exactly defined. The cleaning is usually based on a multi-stage cleaning program that includes various rinsing processes and the use of different cleaning agents. For example, special acids and lyes are used in addition to water. This high speed ensures a turbulent flow, which is essential for the mechanical cleaning of biofilms and particles on the inner walls of the pipelines. In this way, product residues and other production-related impurities disappear from the entire system. This includes the pipes as well as pumps, valves, sensors, sight glasses, and much more.
Lower temperatures and a lower speed are often less successful because, in this case, impurities may still adhere to the system. The verification of the cleaning quality often takes place afterwards with the help of sensors or by taking and checking samples. The effectiveness of the cleaning is demonstrated within the framework of cleaning validation, for example, by the riboflavin test, to ensure that no spray shadows occur in the containers or lines.
How does sterilization work in the SIP process?
The SIP process often uses the same lines as the CIP system but is based on the thermal action of saturated steam. SIP represents an extension of the cleaning process by additionally removing active and harmful microorganisms from the system. This usually happens with saturated steam at 121 to 134 degrees Celsius. In the pharmaceutical sector, saturated steam is used almost exclusively.
Hot water, for example at a temperature of 80 to 95 degrees Celsius, does not serve sterilization but sanitization, the targeted reduction of microorganisms to a level that is harmless to health. The standard value for sterilization with saturated steam is 121.1 degrees Celsius (2.1 bar abs). Values of around 140 degrees Celsius are extremely high, which only unnecessarily burdens the system's seals. The use of chemical agents such as gaseous hydrogen peroxide (VHP) is usually limited to the decontamination of external surfaces and cleanroom areas, but not to the internal fluid path of the BFS system. Chemicals in the SIP step are undesirable in the pharmaceutical fluid path due to residue risks.
The goal of the entire process is absolute freedom from germs, referred to in technical terminology as "sterility." Especially in the production of food, beverages, and medical products, the destruction of potential pathogens has the highest priority. Otherwise, the consumer would be exposed to direct danger. The sterilization process is indispensable in food processing companies and pharmaceutical companies for the simple reason that the companies must comply with strict statutory hygiene regulations.