Top tips for CIP and COP systems

food processing equipment is either cleaned-in-place (CIP) or cleaned-out-of-place (COP).

These cleaning methods offer processors an additional mechanism of process control in that each method CIP and COP systems enhance the ability of the sanitation crew to better clean and sanitize production equipment to a greater degree of food safety and quality assurance .

CIP systems are extremely beneficial for aseptic and other processing operations in which interior surfaces of equipment such as tanks and pips cannot be easily reached for cleaning, and COP methods are utilized for pieces of equipment and utensils that cannot be cleaned where they are used and must be disassembled, and for pieces of equipment that are complex and hard to clean.

With a greater emphasis on sanitary design in food plants, equipment manufacturers and industry have worked together to make many improvements to equipment and parts that make cleaning and sanitizing more effective.

Inside cleaning

CIP cleaning is utilized to clean the interior surfaces of pipelines and tanks of liquid and semi-liquid food and beverage processing equipment. This type of cleaning of generally done with large tanks, kettles or piping systems where there are smooth surface. CIP involves circulation of detergent through equipment by use of a spray ball or spray to create turbulence and thus remove soil. chemical cleaning and sanitizing solution is circulated through a circuit of tanks and or lines to eliminate bacteria or chemical, which then flow back to a central reservoir so that the chemical solution can be reused. The system is run by computer, in a prescribed manner, to control the flow mixing and diversion , temperature and time of the chemicals for cleaning and sanitizing.

As with all cleaning methods, CIP systems utilize time, temperature and mechanical force to achieve maximum cleaning. Automated CIP systems are most commonly used in processes in which liquid or flow-type material is being manufactured. This includes fluid products such as dairy, juice and beverages, as well as in operations using aseptic processing and packaging for low-acid or semi-fluid products such as liquid eggs, sauces, puddings, meal-replacement drinks, aseptic dairy and fruit, jam and marmalade, soups, ketchups and tomato-based products and salad dressings.

Processors also are increasingly finding application for CIP systems in the manufacture of semi-solid foods, such as stews and spreadable cheese. A majority of food manufacturing operation producing these types of products today have installed CIP systems throughout the plant because they are efficient, cost effective and provide effective cleaning of cracks and crevices to reduce the formation of biofilms and growth niches where pathogens and other bacteria can survive. A major advantage of CIP is that it requires less labor since disassembly, manual brushing or scrubbing, rinsing , reassembly and final sanitizing steps are not required. CIP systems also pose little risk to workers, if the system is properly maintained operated. Due to automation of the method, CIP is very effective at containing chemical costs, lowering labor costs, minimizing repair and maintenance to equipment, and allowing the reuse of cleaning solutions.

In general, a CIP operation involves the following steps:

  • Removal of any small equipment parts that must be manually cleaned, making sure that CIP and processing components are clearly segregated. 
  • Cool temperature water (<80F0) is used to pre-rinse the equipment lines and piping to remove gross soil and to minimize coagulation of proteins.
  • After the pre-rinse water is flushed from the lines, the appropriate cleaner solution or treatment is circulate for a requisite period of time to remove any soil, chemical or other residues. This step is followed by another water rinse.
  • The final step is application of a sanitizing agent or method just prior to operation of the equipment. In aseptic operations, this step will be programmed into the system. Sanitizing can be with a chemical rinse or by the circulation of hot water. Hot water is used at high temperatures for CIP of equipment lines on which low-acid products are produced, and acidified water is used in those operations producing acidified or acid-containing products.

Identify and use the right cleaning chemicals and sanitized solutions. It is essential that the right cleaner be employed in CIP systems. The chemical solution or treatment used in the CIP system must be capable of reaching all surfaces, and the surfaces are ideally made of stainless steel, not softer metals. It is recommended that cleaning solution be changed approximately every 48 hours, where applicable.

Some common types of cleaners and sanitizers used in CIP systems include:

  • hypochlorites  (postassium, sodium or calcium hypochlorite). These sanitizing agents are proven sanitizers for clean stainless steel food contact surfaces but the processor needs to maintain strict control of pH and concentration level. Hypochlorites can be highly corrosive, and when improperly used, produces corrosive gas above 115F.
  • Peracetic acid. Peracetic  acid is a combination of hydrogen peroxide, acetic acid (vinegar) and a minute amount of stabilizer that form a strong oxidizing agent. these sanitizers are effective against all microorganisms, including spoilage organisms, pathogens and bacterial spores. Characterized by a strong odor such that you may want to use in well-ventilated areas, peracetic acid solutions are effective over a wide pH range and can be applied in cool or warm water in CLP systems or as sprays/washes in COP processes to all food contact surfaces in the plant.
  • Chlorine Dioxide . if the production line is soiled with high organic loads, such as those found in poultry or fruit processing, chlorine dioxide is good to consider for use in the CIP system. This is because chlorine dioxide is effective against all types of microorganism even when organic matter is present on interior surfaces. However preparation of this chemical should be automated because of its corrosiveness in acid solution.
  • Acid Anionic (organic acids and anionic surfactant).

The combination of an acid with surface-active agents products a cleaning, rinsing and sanitizing solution that is ideal in CIP systems in which the removal or control of water hardness films or milkstone (such as in dairy processes) is critical. Acid-anionic surfactants are effective most bacteria, and are odorless, relatively nontoxic and noncorrosive to stainless steel.


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