Sterilization in Place (SIP)

Sterilization in Place refers to the sterilization of production equipment without prior disassembly. Sterilization is usually carried out by means of superheated steam. SIP systems are used in areas where germ reduction plays a decisive role. Examples are biotechnology or the food industry.

Are CIP and SIP the Same Thing? What Are the Differences?

Steam sterilization of the process plants takes place after CIP (Cleaning in Place) and is the optional final step of the cleaning process.

Process of Sterilization in Place

Sterilization is carried out with steam at 120°C and 2 bar over a period of about 60 to 70 minutes ^[1]. The duration varies according to application and system type.

Challenges of Sterilization With Superheated Steam

Displacement of the air present in the production plant
Increasing the temperature in the entire system to the required sterilization temperature
Avoiding temperature losses and condensate formation

Development of SIP Systems – What to Watch Out For

During the development of SIP systems, especially in the heating-up phase, important questions have to be answered.

Has the sterilization temperature been reached throughout the system?
At what point in the system was the required temperature last reached?
At what points must temperature monitors be installed?
Where are the lowest points of the system, and how can the condensate be blown out? ^[2]

Checklist for Handling After Sterilization

For the safe handling of the system, many details must be precisely defined. They help to maintain the sterility of the process plant after sterilization:

Slight overpressure (sterile air) in the system at all times to prevent the ingress of ambient air
Depending on the product, use sterile, distilled or sterilized water as control, rinsing and/or barrier liquid. ^[1]

Sources:

^[1] Werner H. Stahl: Industrial Centrifuges, vol. II; DrM Press, first edition, 2004

^[2] James Swarbrick: Encyclopedia of Pharmaceutical Technology, third edition