What is the Clean-In-Place (CIP) Method?
Clean-in-place (CIP) is a method of Cleaning & Disinfecting the interior surfaces of pipes, vessels, process equipment, filters and associated fittings without disassembly. The CIP system is run by a digital computer called programmable logic controllers (PLCs) to control the flow, temperature, and time for the chemical solutions, which could be acidic, alkaline or sometimes both, to achieve maximum cleaning. The chemical solutions are circulated through a circuit of tanks and/or lines to eliminate contaminants or product residues and are rinsed out with water. Depending on the CIP system, chemical solutions may flow back to a reservoir so that they can be re-used or drained immediately after they have been used.
After CIP, the equipment should be visibly clean and free from chemical residues. The final water rinse must ensure that chemical residues are removed properly. Chemical residues from cleaning solutions can be monitored by a specific or nonspecific analytical method. Specific methods that detect the individual ingredients of cleaning solutions are ion-selective electrode (ISE), high-performance liquid chromatography (HPLC), thin-layer chromatography (TLC), flame photometry, and ultraviolet spectroscopy. Non-specific methods that detect the presence of a blend of ingredients are pH, conductivity, and total organic carbon (TOC). Specific methods are usually preferable by regulatory agencies, but they may accept non-specific methods with adequate rationales for their use.
As CIP offers fast, repeatable, and effective cleaning without chemical exposure risk to people, it is utilised in industries that require high levels of hygiene such as dairy, beverage, processed foods, pharmaceutical, and cosmetics. CIP is typically employed for cleaning bioreactors, fermenters, mix vessels and other equipment in manufacturing facilities and many CIP systems use alkaline cleaning solutions containing 0.5 to 2% (by weight) caustic soda or sodium hydroxide (NaOH) to remove fats and proteins.
Sodium Testing
You can use a sodium meter to measure and monitor residual sodium ion (Na+) concentration during CIP in process plants. This will help you to gain an accurate measurement that will complement the cleaning efficiency of CIP.
Using a sodium meter (such as the LAQUAtwin B-722 sodium ion meter), calibrate the meter according to manufacturer’s instructions. Rinse Water Sampling and Wipe Sampling are two sampling methods for measuring cleaning chemical residues (a combination of these is desirable). Rinse Water Sampling involves taking a sample of an equilibrated water rinse (usual water for injection or pure water) that has been recirculated over all surfaces.
To measure, place drops of rinse water sample onto the sodium ion sensor using a pipette. Alternatively, open the sensor guard and soak the sensor into a beaker containing rinse water. Swab or wipe sampling is done directly on equipment surfaces. This is performed in order to assure that the residues are being adequately detected and not simply sitting on the surface and not being dissolved into the equilibrated rinse water. Before wiping begins, moisten the sampling sheet (usually sold separately) with water for injection or pure water and allow the equipment to dry after the cleaning procedure. Then wipe the surface with a moistened sampling sheet and place it onto the sensor. Blank preparation is required for this sampling method.
Results and Benefits
Cleaning validation is a critical part of current good manufacturing practice to ensure that production materials that come in contact with Lab Equipment Suppliers surfaces are not contaminated. The pre-rinse, alkali circulation, and other steps must take place in the correct order. Checks on the identity, purity and strength of cleaning chemicals and on quality of water used for rinsing are needed. Also, the validation protocol must include testing for the residual cleaning chemical to ensure that cleaning chemical used is properly removed. The analysis must be quantitative and the acceptance criteria are determined according to regulatory guidelines and company policy.