Cleaning & Sanitizing for Food Plants

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Introduction

All equipment must be cleaned and sanitized prior to use and following any pause in use that could result in contamination.

Specific procedures (SOPs) for cleaning & sanitizing each piece of equipment are available to the operator

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Principles of cleaning & sanitizing

Cleaning: removal of soil from surface

Sanitizing: reducing level of microorganisms on surface to reduce food contamination

Biofilm: food & bacteria left on equipmentRemoval requires energy

Physical / chemical / heatUse of detergents reduces energy

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Main purposes of cleaning

Remove soils that harbor microorganisms and provide nutrients for their growth

Prevent the transfer of ingredients from different batches of products

Eliminate soils that affect efficiency of heat transfer Prolong equipment life by removing potentially

corrosive materials Facilitate preventive maintenance

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Cleanup steps

Pre-rinse Removes gross soils (reduces need for chemicals)

Wash Removes most bacteria by chemicals, heat, agitation

Post-rinse Removes most bacteria and soil loosened by washing

Sanitize Ensures that equipment doesn’t

contaminate incoming product Doesn’t compensate for poor wash

“You can’t sanitize dirt!”

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Cleaner selection

Factors to be considered when selecting cleaning chemicals

Nature of soil Organic / protein / petroleum-based / inorganic

(scale or oxide) Nature of surface to which soil is attached

Stainless steel / aluminum / rubber / plastics Quality of water available

Use potable water Hardness (Ca / Mg) will affect performance

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Cleaning methods

1. Manual Taking equipment apart & using brushes

2. Cleaning-Out-of-Place (COP) Taking eqpt apart and using tank for soaking

3. Cleaning-In-Place (CIP) Using circulating solution without taking eqpt

apart

4. Pressure spraying Using high or low pressure

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Manual cleaning

Uses lower concentrations of chemicalsCleaners are formulated for safe useBrushes are used to apply physical

energyVery labor intensiveComplete cleaning may be difficult if

physical energy is not consistent

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Cleaning out of Place (COP)

Requires little labor Good penetration during soaking Needs good arrangement of parts and agitation

to work effectively Cleaner needs to be selected because of long

soaking time

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Pressure spraying

Effective for cleaning large areasE.g. floors, walls, irregular areasFoaming cleaners on walls

Temperature is reduced on contactPhysical energy varies with proximity

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Effective cleaning

Procedures include:Contacting the soilAllowing sufficient contact time to reactMaintaining temperatureProviding sufficient energy

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Mechanism of cleaning

Detergent is dissolved in waterSolution is applied to surface to separate

soilWater soluble soils are dissolved in waterCleaner allows water close contact to

surfaceCleaner then loosens soil by reducing its

attraction to surface

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Mechanism of cleaning (2)

Soil separation is helped by physical action Scrubbing / turbulent flow / pressure spray

Soil dispersion begins Soluble soils remain in cleaning solution Clumps of insoluble soil are broken down Fats & strong alkalis create a soluble soap

Cleaner and dispersed soil are removed Surface is rinsed with potable water to remove

cleaning solution

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Cleaner performance

Four factors for cleaner effectivenessTime

15+ minTemperature

60-70C (140-160F) preferredConcentration of cleaner

Recommended by manufacturerPhysical energy

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Cleaning Variables

TemperatureTime

Concentration Velocity

Concentration

Temperature

Time TimeTemperature

ConcentrationVelocity

Velocity

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Purpose of sanitizing

Last step in cleanup processRequires proper cleaning of surface first

Remove oil / biofilm / cleaner residueReduces microorganisms on previously

cleaned surface free of pathogens

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Ideal sanitizer

Has a rapid kill and wide spectrum of kill Exhibits good environmental resistance

Not adversely affected by poor water quality or residues

Effective over wide pH range Non-toxic to humans Non-corrosive to surfaces under all conditions Freely soluble Good shelf life

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Effective sanitizing

Use at recommended concentration More can cause corrosion

pH of sanitizer is formulated for best action Kill increases with temperature

Stability can decline

Time of exposure varies Must be capable of 99.999% kill in 30 sec Contact time of 2 min is common

Residual soil affects performance of oxidizers

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Proper operation & cleanup

Promptly rinse equipment after use with cool to warm water

Properly maintain equipmentSeals and gaskets

Keep work area cleanReduces amount of difficult cleaning

Follow predetermined schedulesUse chemicals for intended use /

concentration

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Portable equipment

Store properly when not in useKeep from splashing / dust

Re-sanitize before next useClean and sanitize if brought out of

storage

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Equipment cleanup procedures

Remove all product and debris from equipment

Have sufficient room between walls / equipment to allow for cleaning

Have sufficient space underneath equipment for cleaning or seal

Disassemble equipment as necessary: Remove / replace shields Clean horizontal debris catchers Remove / replace product contact surfaces

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Equipment for cleanup

Washing equipment considerations include: High pressure systems

Central / portable

Mixing valves (steam + cold water) or hot water systems Raise temperature for cleaning

Proportioning pumps / venturi-metering / foamers

Minimize water use to limit sewer loads

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Manual cleaning

Completely disassemble equipmentRinse manuallyBrush with cleaning solutionRinseSanitize

Before reassemblyJust before processing

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Remember!

Remove all productClean up first using scrapers / broomsThen clean thoroughly, paying close

attention to product contact surfacesSanitize clean area so that it doesn’t

contaminate new product