Disinfection with CIP

Cleaning-in-Place (CIP) equipment is best used for cleaning pipelines, vats, heat exchangers, centrifugal machines and homogenizers. CIP systems can vary in amount of automation according to cleaning requirements. Indeed, there are a number of steps involved in a full cleaning and sterilising CIP process :

Flushing
Alkaline cleaning operation (caustic)
Intermediate water rinse
Acidic cleaning operation
Final water rinse

Selection of the detergent depends on the soil, on the target microorganisms and the cost.

The caustic wash is not a sterilising process. Spores and hardy microorganisms are able to survive the caustic wash. So disinfection/sterilisation requires the use of a sanitising wash. A variety of chemicals are available for the sanitising wash. These include chlorine compounds (such as chlorine dioxide), ozone and hydrogen peroxide.

Comparison between chemicals sanitisers :

Ozone

Chlorine dioxide

Hydrogen peroxide

Advantages

- High oxidation power (so improves CIP effectiveness)

- No taste or odor is associated with its use

- Generated on-site, so no dangerous storage or handling is required

- Without chemicals residues

- Disinfects faster than conventional chemicals, saving time and money

- Reduces rinse-up time

- High strength disinfection with minimal environmental impact

- Produces no organic chlorine compounds with contaminants most frequently found in water, and the compounds eventually formed are largely negligible in terms of sensory of toxicity consideration

- Suppresses the forming of the volatile haloforms and reduces the generation of non-volatile organic halogen compounds

- Cheap disinfectant agent

- Microcidal action can be increased by the addition of peracetic action

- Very effective

- No chemical residues

Disadvantages

When there are no organics left to destroy, dissolved ozone will be detectable in water leaving the equipment

- Corrosiveness to stainless steels

- Formation of organochlorides if it not removed properly

- Relatively expensive

- Corrosive (as pure H₂O₂)