CIP vs. SIP: More than just cleaning

Do you know the differences between CIP and SIP cleaning? 

Within the food industry, cleaning of process equipment is extremely important – not only to ensure compliance with the most common hygiene standards, but also to be able to produce food of the very highest quality in the most efficient way. 

We regularly receive questions from customers about CIP and SIP. That is why, in this article, we are focusing on these cleaning methods, their differences, how the processes work step by step, and the products we often recommend depending on production conditions and cleaning method. Whether you are a brewery, a dairy, or a pharmaceutical manufacturer, proper cleaning is the foundation of your product safety. 

Read along and become a master of the topic! 

Thorough and correct cleaning of the processing plant forms the foundation for efficient and safe food production, which both minimises the risk of contamination and, in the worst case, personal injury, and complies with the industry’s food safety standards, such as those set by the EU and the FDA (Food and Drug Administration). 

The consequences of inadequate cleaning extend far beyond a single discarded batch. Product residues of fat, protein and sugar provide a breeding ground for biofilm – thin layers of microorganisms that settle on internal surfaces and become increasingly difficult to remove the longer they are allowed to grow. At the same time, cross-contamination between production runs is a real risk if the plant is not thoroughly cleaned between batches. This applies to allergens, microorganisms and chemical residues alike. 

At a time when consumer awareness of food safety is at its highest, companies’ commitment to clean production processes can directly impact their reputation and thus their competitiveness in the market. Therefore, cleaning is not a cost, but an investment in operational reliability, documentation and brand reputation. 

CIP (Clean-in-Place) and SIP (Sterilize-in-Place) are the two most common methods in the process industry for cleaning and sterilising equipment without the need for dismantling. The two methods are often confused, but they each serve a distinct purpose – and are often used in practice in conjunction with one another. 

CIP cleaning, which is often a fully automated process, involves, for example, a caustic solution or lye being circulated through machines and pipework to remove product residues and microbial deposits. The process ensures thorough and effective cleaning without the need for manual labour. CIP cleans – but does not necessarily sterilise. 

SIP cleaning involves the application of steam or other sterilising agents to achieve a sterile environment inside the equipment. Whereas CIP removes visible and microbial dirt, SIP kills the remaining microorganisms. This method is used in production environments where sterility is essential, such as in the pharmaceutical and biotechnology industries. 

The effectiveness of a CIP cleaning depends on a precise balance between chemistry, time, temperature and mechanical action – and on the entire process being able to run in a closed system without time-consuming dismantling of the plant. The sequence itself depends on the product being manufactured, whether it's beer, milk, spirits or various types of edible oils, but the following steps are often included in chronological order: 

• Rinsing with water to remove coarse dirt and loose product residues. 
• Rinsing with a caustic solution, such as lye, which breaks down fats, proteins and organic dirt. 
• Rinsing with an acidic solution, such as nitric acid, which removes mineral deposits and neutralises the plant after the lye wash.   
• Rinsing with water to remove the last traces of chemicals. 
• Optional disinfection using a suitable disinfectant or steam. In some production processes, particularly in the pharmaceutical industry, this step is mandatory to eliminate any remaining microorganisms. 

It may sound straightforward, but each individual step places demands on all components, particularly hoses and couplings. It's important that the entire setup is designed to withstand the load to ensure a stable process. 

Whereas CIP uses chemicals, SIP uses steam and heat. The aim is to bring all internal surfaces up to a validated sterilisation temperature and maintain it for a defined period of time. This is typically achieved using saturated steam at approximately 121–134 °C, depending on the process, equipment and validation requirements. 

For SIP to be successful, three things must be in place: 

• The air must be removed: Trapped air forms ‘cold pockets’ where the steam does not reach the sterilisation temperature. Air and condensate must therefore be able to be vented away. 
• Condensate must be able to be drained: The system must be able to be emptied completely so that no liquid remains. 
• No dead zones: Narrow pockets, valves and blind hose tails (“dead legs”) are the weak points of sterilisation because the steam does not circulate there. 

Choosing the right hose is critical to achieving the desired cleaning results, and it always depends on the chemicals, temperatures and pressures the hose must be able to handle. A hose that does not match the chemistry, pressure or temperature is one of the most common causes of breakdowns, leaks and contamination. A tight and hygienic CIP/SIP loop depends not only on the hose itself, but also on the hose couplings and fittings that hold the system together. 

For CIP cleaning with lower concentrations of cleaning agents, Alichem/SPL is a good choice; it is made from EPDM rubber with a built-in steel spiral, making it both flexible and robust. If, on the other hand, you are working with concentrated acid or strong chemicals, you should choose FoodForce C, where the Teflon material offers far greater chemical resistance than EPDM and retains its shape even as the temperature rises. 

For SIP cleaning, it's crucial that the hose can withstand steam in terms of both temperature and pressure: for open steam sterilisation without pressure build-up, the food-grade Food Steam is suitable, whilst for pressurised steam you should use a steel reinforced hose such as Soffione or FoodForce C, which are designed for high temperatures under pressure – please note, however, that Soffione is not food-approved and should therefore only be used where the hose is not in direct contact with the product.  

Regardless of which hose type you choose, it's important that the hose has the necessary approvals and standards for the application. All materials in direct contact with the product must comply with the relevant food regulations and compliance requirements, which cover both material safety and production quality control.

When CIP or SIP cleaning fails, it's rarely due to the method itself – but often to design, choice of materials or settings. The most common pitfalls are: 

• Incorrect choice of materials: Hoses and gaskets that cannot withstand your cleaning agents or steam temperatures will degrade and leak. 
• Dead legs: Pockets, blind hose tails and tight angles where the liquid or steam does not circulate become hiding places for bacteria. 
• Incomplete drainage: If the system cannot be emptied completely, liquid remains – a breeding ground for bacterial growth. 
• Incorrect concentration or flow: Too low a chemical concentration or flow rate results in inadequate cleaning; too high a concentration or flow rate can damage equipment and the product. 

Many of these issues can be prevented right from the design phase by incorporating hygienic plant design and the correct choice of components from the outset. 

We want to be more than just your equipment suppliers. We are also your partners in production hygiene. Our team of experts is ready to guide and advise you on the best solution for your specific needs, whether it concerns CIP or SIP cleaning. 

Contact us by email inquiry@alfotech.eu or by phone +45 7020 0422 for a no-obligation chat about how we can help you optimise your cleaning processes and ensure your production runs like clockwork. 

CIP is an internal cleaning process using chemicals to remove product residues and bacteria – without dismantling the system. SIP goes a step further and sterilises using steam or similar methods to ensure all microorganisms are removed. Whereas CIP is typically used in food production, SIP is necessary in environments requiring full sterility, such as the pharmaceutical industry. 

Yes, and many already do this as standard. First, you remove residues and bacteria with CIP, then you sterilise with SIP. It's an effective solution in production environments with high hygiene requirements. You save time, minimise manual handling and ensure consistent cleaning quality without the risk of cross-contamination. 

The two main types of chemicals are lye (sodium hydroxide), which breaks down fats, proteins and organic dirt, and acid (typically nitric or phosphoric acid), which removes mineral deposits and limescale. A disinfection step is often added to this. Which agents and concentrations are best depends on the product and the type of dirt – and it's crucial that hoses and gaskets are resistant to the specific agents you use. 

It depends on the chemicals, temperature and pressure. Start by looking at which media you use – and in what concentration. Steam and closed systems place extra demands on pressure and temperature tolerance. Choose materials that match both the medium and the process, and assess whether reinforcement is required. You can also assemble the hose to your specifications using our hose configurator. We are happy to advise you so that you get a solution that suits both cleaning and production. 

Avoid materials that cannot withstand your cleaning agents, and be mindful of pressure conditions and temperature. Use the correct concentration, and avoid dead spots such as pockets and tight angles where the liquid does not circulate. Also ensure that the system can be completely drained. Otherwise, you risk bacterial growth and contamination.