What is a CIP System and Why is it Important in Food Facilities?
CIP (Clean-In-Place) is an automatic system that cleans tanks, pipes, and filling machines by circulating the cleaning solution in a closed loop without disassembling them. The European Union's (EC) Regulation 852/2004 on food hygiene requires the effective cleaning of equipment that comes into contact with food and, when necessary, its disinfection. The Codex Alimentarius's General Principles of Food Hygiene (CXC 1-1969) also mandates the monitoring and verification of the cleaning program. CIP meets these two requirements with repeatable temperature, time, and chemical concentration; data from each cycle is recorded. In dairy, sauce, paste, and beverage plants, CIP is not an added device to the line but rather a deliberately designed infrastructure from the outset.
How does CIP work?
The CIP unit consists of water and chemical tanks, a feed pump, a heater, a return line, and conductivity and temperature sensors. The cleaning solution is circulated through the process line at a specific speed and temperature. The effectiveness of cleaning is the sum of four factors: chemical action, temperature, contact time, and the mechanical effect of the flow. Any deficiency in one effect must be compensated by the others. ASSUMPTION: The common design target for mechanical effect in pipes is a flow rate of at least 1.5 m/s. In tanks, the solution is sprayed onto the inner surface using a spray ball or rotary head. The conductivity sensor in the return line automatically manages the phase transition by measuring the transition between rinse water and chemical. As a result, the same program is repeated under the same conditions in each cycle.
What steps does a typical CIP program consist of?
A typical CIP program is a five-step sequential cleaning cycle from pre-rinsing to final rinsing. First, the pre-rinse removes coarse residues; then, caustic washing dissolves fats and proteins. After the intermediate rinse, acid washing removes mineral deposits (milk stone), and the final rinse removes the chemical from the line.
| Step | Purpose | Typical Value (ASSUMPTION) |
|---|---|---|
| 1. Pre-rinse | Remove coarse product residues | Reclaimed final rinse water |
| 2. Caustic washing | Dissolve fats and proteins | 1–2% NaOH, 70–80 °C |
| 3. Intermediate rinse | Remove caustic | Until conductivity drops |
| 4. Acid washing | Dissolve milk stone | 0.5–1% nitric or phosphoric acid, 60–70 °C |
| 5. Final rinse | Remove chemical residues | Verified by conductivity |
The acid step is routine in dairy lines; caustic-heavy programs are prioritized in sauce lines. If necessary, disinfection or SIP is added after the final rinse.
What is the difference between manual cleaning and CIP?
Manual cleaning is a method where equipment is disassembled and washed by hand; CIP performs the same task in a closed loop with recorded parameters.
| Criterion | Manual Cleaning | CIP |
|---|---|---|
| Inside pipes and tank tops | Inaccessible by hand | Solution reaches all inner surfaces |
| Repeatability | Operator-dependent | Temperature, time, and concentration are the same in each cycle |
| Record | Handwritten form | Sensor data is automatically logged |
| Water and chemical | Full consumption in each wash | Reuse with recovery tank |
| Operator safety | Direct contact with chemicals | Closed loop, limited contact |
Biofilm forms in areas inaccessible by hand, such as inside pipes and tank tops. Therefore, in lines processing milk and acidic products, CIP is one of the first systems inspected during audits.
Example sizing: 5,000 L tank + 200 m pipeline
Example sizing is an exercise in calculating the main components of the CIP unit derived from the line size.
- Pipe flow rate: ASSUMPTION: DN50 milk pipe inner diameter 47.8 mm → cross-sectional area approximately 0.0018 m²; for 1.5–2.0 m/s, Q ≈ 9.7–12.9 m³/hour
- Tank cleaning: For a 5,000 L vertical tank, in most cases, a single spray ball is sufficient; flow is selected from the manufacturer's table
- CIP tanks: ASSUMPTION: 3 × 1,000–1,500 L is a typical starting point for caustic, acid, and recovery water
- Heating: Plate heat exchanger or electric or steam heater for 70–80 °C caustic
- Program duration: ASSUMPTION: 45–90 minutes from pre-rinse to final rinse
As the length of the line, number of tanks, and number of circuits increase, values become clearer in the project. The space left for later-added CIP is often insufficient.
What should be considered in CIP design?
Hygienic design is the layout of the line that leaves no dead volume unreachable by the cleaning solution. For tanks to be CIP-able, properly positioned spray balls, valve selection that leaves no dead volume, and self-draining piping are required. ASSUMPTION: A common practice in pipes is approximately 1% slope. Dead legs are kept short; branches are placed according to the flow direction. Additionally, the number of circuits is determined from the outset: tanks, process lines, and filling machines can be separate circuits. AISI 304 or 316 stainless steel is used for product contact surfaces. As a result, CIP is designed on the same drawing as the line layout.
CIP planning checklist
The planning checklist is a set of information that ensures the correct sizing of the CIP unit before the proposal.
- Circuits to be cleaned: tanks, process lines, filling machines, and number of circuits
- Product profile: is it oily or protein-rich (caustic-heavy), does it create mineral deposits (acid step)
- Number of daily cleaning cycles and frequency of product transitions
- Desired level of water recovery and wastewater neutralization
- Chemical storage area and operator safety equipment
- Sensor and logging needs (for auditing and traceability)
All six pieces of information ensure that the CIP unit is sized in the same round as the line proposal.
When is disinfection and SIP required after CIP?
Disinfection is an additional step that reduces the microbial load after chemical cleaning; SIP (Sterilize-In-Place) is the steam sterilization of the line in place. ASSUMPTION: Hot water sanitation is typically performed with circulation at 85–90 °C. Cold disinfectants like peracetic acid are preferred in heat-sensitive circuits. SIP is standard in aseptic filling lines; hot water sanitation is often sufficient in classic pasteurized products. The correct question is not "which is best" but rather which one is required for the product's shelf life target.
How can water and chemical consumption be reduced?
Recovery is the reuse of final rinse water and caustic solution in the next cycle. A well-designed CIP collects final rinse water in a recovery tank and uses it in the next pre-rinse. The caustic solution is monitored for concentration through conductivity control and evaluated over many cycles. In a simple system without recovery, each cycle consumes full water and full chemicals. In a facility that performs 2–3 cycles per day, the difference appears as a separate line in the annual operating budget. It is also checked whether there is a recovery tank and conductivity sensor in the proposal.
How is the cleaning verified?
Verification is the record system that proves not that CIP is working, but that the surface has indeed been cleaned; Codex CXC 1-1969 and ISO 22000:2018 require monitoring of the effectiveness of the cleaning program. Verification is established on three layers. The first layer is the process record: temperature, time, and conductivity data for each cycle are automatically logged. The second layer is rapid tests: ATP measurement from swabs taken from critical points provides results within minutes and is included in the shift routine. The third layer is periodic microbiological analysis: samples are taken from final rinse water and product contact surfaces as per the plan. When the three layers are combined in a file, cleaning becomes a record, not a claim, for customer audits and official inspections.
What are common CIP mistakes?
Common mistakes are cleaning gaps arising from the CIP unit being incorrectly selected and improperly operated.
1. Low circulation speed: the pump is correct, but the pipe diameter has been increased; ASSUMPTION: Below 1.5 m/s, the mechanical cleaning effect decreases.
2. Estimating concentration by eye: chemicals are dosed by hand when a conductivity sensor is present.
3. Clogged spray ball: silent contamination accumulates on the tank top.
4. Dead legs: subsequently added branches leave dead volume that the solution cannot reach.
A simple monthly CIP performance check (flow rate, concentration, temperature, and spray ball observation) captures all four mistakes.
Related solutions
- Dairy Processing & Pasteurization Line — a typical line where CIP is routine
- Sauce Production Line — CIP plan during recipe transitions
- Pasteurizer and Plate Heat Exchanger — thermal processing equipment with CIP integration
- Guide to Setting Up a Dairy Processing Plant — facility flow from acceptance to filling and cold chain
Frequently Asked Questions
Is CIP necessary in a small facility?
CIP is recommended for all scales processing milk and acidic products; the equipment cleaning requirement of Regulation (EC) 852/2004 is independent of facility size. Compact single-tank CIP units are an economical starting point for small lines. The main gain in a small facility is that cleaning is no longer dependent on the operator and each cycle is recorded. For example, a single-tank CIP unit in a dairy processing 1,000 liters of milk per day can clean the pasteurizer and filling line in a single cycle. Additionally, Codex CXC 1-1969 requires monitoring the effectiveness of the cleaning program; automatic recording facilitates this monitoring.
How much time does CIP take from production?
ASSUMPTION: A typical CIP program takes 45–90 minutes from pre-rinse to final rinse. The duration is determined by the length of the circuit, the number of tanks, and whether the acid step is applied. The program is scheduled around planned shift breaks; the recovery tank and automatic phase transition shorten the duration. In sauce lines with 2–3 product transitions per day, short intermediate rinses can be used instead of the full program. The full program is applied at the end of the shift or when changing product families.
Do CIP chemicals leave residues in the product?
With proper final rinsing and phase separation using a conductivity sensor, no residues remain. The sensor measures when the conductivity of the return water drops to that of clean water and ends the rinse at that point. Therefore, systems with sensors are preferred; periodic samples from the final rinse water are also taken for verification. ISO 22000:2018 and Codex CXC 1-1969 consider the verification of cleaning as part of the food safety system. Records of chemical concentration and final rinse conductivity value are kept in the same file.
What is the difference between CIP and SIP?
CIP is chemical cleaning; SIP (Sterilize-In-Place) is the steam sterilization of the cleaned line in place. SIP is standard in aseptic filling lines. In classic pasteurized products, hot water sanitation after CIP is often sufficient. The decision is made based on the product's shelf life target. ASSUMPTION: Hot water sanitation is typically performed with circulation at 85–90 °C; SIP is applied at higher temperatures with saturated steam and is included in the design of the aseptic line from the outset.
Next Step
To size your line's CIP needs according to your product, share the product type, number of tanks, and daily cleaning cycle. ProcessTürk engineers will also report the cleaning scenario in the preliminary assessment. You can request a preliminary assessment from the custom project page or contact our team via the contact page.