What is Clean-In-Place (CIP)?

Reviewed by Daryl L. Roll P.E.
  • November 9, 2021

It is not a stretch to say that the hygiene and cleanliness of a food or pharmaceutical manufacturing system is as critical as the ingredients being processed within it. Minor lapses in sanitary best practices can have broad reaching effects upon the consumer as well as the brand. For this reason, many modern food and biopharmaceutical production systems have at least some sections designed with a Clean-in-Place (CIP) system as an integral component.

In addition to the food and beverage and biopharmaceutical industries, CIP systems can also be found in production plants in the cosmetic and household personal care industries. Regardless of which industry, the objective of the CIP system is the same – to provide the operator with a reliable and repeatable way to clean their processing plant with minimal downtime.

What is a Clean-in-Place System?

At its most basic, a CIP system delivers cleaning, rinsing and sanitizing solutions to the interior contact surfaces of process piping vessels, mixers, fillers, blenders, fermenters and other equipment within a processing system. By its nature, it will use much of the plant’s plumbing. However, there will be a separate CIP tank with dedicated valves, heat exchangers and its own set of sensors and control hardware. Additionally, tanks will have spray balls to ensure that the cleaning solution is applied to the entire interior surface.

CIP Cleaning Process

Even though CIP technology has come a long way from the first manually operated systems of the 1950s, they still rely on the same principles to clean the host system reliably. In 1959, Dr. Herbert Sinner created what is referred to as the Sinner’s Circle. Dr. Sinner was a German chemical engineer who headed the development of detergents for Henkel, the West German chemical and consumer goods company. His circle described the cleaning process as a combination of four components: time, chemistry, mechanical action and temperature.

Dr. Sinner used his circle to describe how different amounts of each component could affect the final cleanliness. In a CIP system, this results in a custom-tailored concentration of chemistry at a specific temperature which is circulated for a set amount of time. The mechanical action in this case is the velocity at which the cleaning solution is circulated as well as the pressure coming from any spray balls. Some systems will use higher temperatures and lower pressures. Others will use a high pressure flow to ensure a proper clean. The configuration of the plant and the nature of the contamination to be cleaned are key factors in determining the proper method. Depending on the product and the operator, a CIP cleaning is run between batches or it is run when the production system is switching over to a different product. Typically, a cleaning consists of a pre-rinse, a heated chemical cleaning, an intermediate rinse followed by a final rinse and then a sanitizing rinse.

Benefits of a CIP System

The two most obvious advantages of having a CIP system integrated into a processing plant are the repeatability of the cleaning process as well as the time saved by not having to disassemble components for cleaning. Those two broad advantages translate into more specific ones:

  • Process Consistency – No missed steps, no missed residue, no wrong combination of chemicals, etc.
  • Quality Assurance –Quality assurance is easier to maintain due to the reduction in contamination risk.
  • Environmental & Employee Safety – Not only is there a reduced chance for a chemical spill due to the closed nature of the system, personnel are not exposed to the chemistry.
  • Faster Turnaround Time – The production plant can get back to making new product sooner

In short, a CIP system is a tool to help maintain a system between scheduled shutdowns. Its use can help prevent unplanned shutdowns.

What a CIP System Cannot Do

A Clean-in-Place system is designed to do precisely that – clean its host production system. However, the presence of rouge may present challenges for most CIP systems. There are a variety of types and sources for the iron-based contaminant, each requiring unique chemical blends and processes to remediate. CIP systems use commercially available chemicals and in fairly large quantities. These chemicals have some superficial similarities to those used by high purity cleaning companies such as Astro Pak. These end-user chemicals are formulated to work for an “average” application for a wide range of industries, rather than being tailored to fit a specific cleaning challenge. It’s the difference between buying bug spray at the grocery store and having a professional pest control expert target a specific problem with just the right amount of pesticide.  Additionally, a derouging service will often have to go where the CIP components are not. A proper derouging treatment will involve utilizing the CIP system, but not being limited to it. In this way, the contamination can be removed more quickly and more thoroughly.

Likewise, while CIP is useful when performing maintenance cleaning of a system, it is not the proper startup process when commissioning a new system. In a new system, residue left from its construction, un-passivated welds and even surface damage left by mechanical cleaning must all be addressed in order to ensure purity of the product from day one. Welds may need to be electropolished and/or passivated, as will any mechanically polished surfaces to ensure a clean system from the start. Typically, CIP flow paths and velocities do not adequately flush out all construction debris especially metallic shavings that will prematurely corrode the system. However, by using the CIP system’s plumbing in addition to temporary lines and pumps, the system can be properly cleaned and made ready by a high purity chemical cleaning provider.

In the case of expanding a facility, bringing in an Astro Pak team with its self-contained setup, eliminates the need to divert resources from current operations servicing existing systems. Astro Pak’s teams bring in state-of-the art skids with high velocity flowrates to provide a deeper, more thorough clean than can performed with a CIP system. The skids’ filtration systems capture particulate matter during the rinse cycle to prevent recontamination. These skids are able to process multiple systems simultaneously to maximize chemistry and resources while reducing downtime.

Another important process that is needed to keep a stainless steel production unit operating smoothly is passivation. As regular readers of Astro Pak’s blog are familiar, passivation is restoring and maintaining the steel’s chemically inert passive layer so that it does not affect, and is not affected by, the material coming in contact with it. That need for passivation also extends to the CIP system itself. CIP systems are almost entirely fabricated from stainless steel and because they are embedded within the processing system, the CIP’s components are affected by the same conditions as the surrounding system.  Passivating the CIP parts often require manual application of gels and other passivating chemistry to ensure that no areas are left untreated. Additionally, Astro Pak’s UltraPass® passivation achieves a chrome-to-iron ratio that is unmatched in the industry, imparting the most optimal passive layer to the surface of stainless steels. Moreover, most of the cleaning and passivation chemical blends Astro Pak uses are biodegradable, ensuring the safety of personnel and the environment.

CIP Gone Awry

However, as clear a benefit as the automated CIP process is, it’s not entirely a set-it-and-forget-it process. Change in product or system alterations require concurrent CIP modifications to ensure efficacy. On the other hand, a poorly engineered design can lead to premature corrosion and damage to the system and equipment it was designed to protect. In one such instance, Astro Pak’s experts identified that the spray balls had damaged the stainless steel in some tanks. CIP Cleaning RougeThe holes in the balls were too small, so the cleaning solution sprayed out at a higher pressure and had physically worn away the passive layer and pitted the metal underneath. This damage had gone on for an extended period because the closed nature of the cleaning process did not lend itself to frequent visual inspections. While the facility’s on-site crew dismissed the damage as discoloration from use, Astro Pak was able to quickly identify the problem and recommend a modification, saving the facility spoiled production batches and extensive repair downtime.

CIP is Just One Step

CIP is a process that not only helps ensure product purity, but it also supports the continual, reliable operation of the plant. As noted above, it is only one procedure out of a more comprehensive plan. Derouging should be considered a critical part of this plan. Depending on the system and product, bioburden remediation may also need to be performed on a regular basis. Use of a CIP system along with regular derouging, chemical cleaning and passivation services together make a multi-layered approach to preserving the integrity and function of the system.

Posted by Astro Pak Marketing Category: Blog
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