4 Chemicals Commonly Used in a CIP Cycle

Advantages of a CIP System:

• Minimizes Mistakes: Automating cleaning reduces the chance of human error that can contribute to an unsafe product.

• Keeps Employees Safe: Reduces chemical exposure by containing cleaning solutions within the system.

• More Production Time: As less production time is lost to cleaning, more time is spent making product.

• Product Quality: Reliable and repeatable cleaning means sustainable product quality and consistency. Less contamination means fewer product recalls and higher brand confidence.

• Utility Savings: Water and energy usage is reduced through repeatable cycle control.

1. Caustic

Also known as caustic soda, sodium hydroxide or NaOH. This is an alkali with a very high pH that is typically used in a concentration range of 0.5-2.0%. Concentrations as high as 4% may be used for highly soiled surfaces.

• Typically used as the main detergent in most CIP wash cycles
• Softens fats, making them easier to remove
• Non-foaming formulation can help reduce pump cavitation and increase efficiency

2. Acid

Nitric acid is the most commonly used wash for scale removal and pH stabilization after a caustic wash. At a typical concentration of 0.5%, it can be used effectively at lower temperatures than caustic solutions, requiring less heating.

Phosphoric acid is sometimes used but is somewhat less common.

• Used by dairies regularly to remove milk scale or “milk stone”
• Excellent for brightening up discolored stainless steel by removing calcified mineral stains
• Must be used with caution because they can attack some elastomers in the system like gaskets or valve seats causing premature degradation or failure

Tip: Acid wash should not precede a caustic wash when removing milk deposits as acid could cause protein precipitation thus making the deposits more difficult to remove

3. Sanitizer/Disinfectant

The job of a sanitizer, also referred to as a disinfectant, is to reduce microorganisms to a level where they don’t pose a risk to food safety or public health.

For many years various hypochlorite solutions (potassium, sodium or calcium), also known as “hypo,” have been used as sanitizers in many CIP cycles.

Their active ingredient is chlorine (bleach) so they

• Are relatively inexpensive to use
• Are very effective as a sanitizing rinse for soils that are prone to bacterial growth such as dairy products
• Can be very harmful to stainless steel, causing staining, corrosion and pitting
• Can cause some significant environmental problems when dissolved in wastewater streams by killing vital microorganisms in streams and waterways

4. Sterilizer

Sterilizing a system means completely eliminating all living microorganisms. Sterilization can be done using chemicals but it is usually done with high pressure steam (approx. 250° F for 30 minutes).

While food, dairy and beverage processing plants seldom require sterilization in their CIP process, it is a common cleaning operation for pharmaceutical or extended shelf life (ESL) products.

Tips For Recovery and Re-Use of Chemical Solutions

Environmental impact issues and chemical costs in the 1960s and 1970s drove the move to CIP systems that could re-use caustic and acid solutions. In situations with light to moderate soiling, wash solutions can be returned to their appropriate CIP tank and re-used for subsequent cycles. The number of re-uses varies by chemical concentration and amount of soiling, but re-using some solutions for dozens of washes is not uncommon.

TIP: For heavy soiling applications, re-using the wash solution isn’t practical, so it is typically sent to drain after a single use. Also, a single-use system should always be used if your cleaning protocols demand that absolutely no cross-contamination occur between batches.

How to Calculate Proper Cleaning Temperature

Calculating accurate solution temperature is critical to effectively cleaning your system while reducing energy costs. Some studies have shown that every one-degree reduction in CIP solution temperature reduces energy needs by 1%, Which can result in significant savings over the course of a year.

We know that higher solution temperatures can increase the effectiveness of chemicals and mechanical action; they can also reduce the amount of time needed to clean properly. But considering the cost of energy to heat the solution, it is important that the temperature of each individual cleaning stage be calculated and controlled as accurately as possible.

Each stage of the cleaning process has its own optimum temperature range to balance effective cleaning with energy conservation. To the right are some typical CIP temperature ranges.