UWIC Managing Cleaning :Validation, Monitoring and Verification of Cleaning Programmes Prof Chris Griffith Food Research and Consultancy Unit University

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Managing Cleaning :Validation, Managing Cleaning :Validation, Monitoring and Verification of Monitoring and Verification of

Cleaning Programmes Cleaning Programmes

Prof Chris GriffithProf Chris GriffithFood Research and Consultancy UnitFood Research and Consultancy Unit

University of Wales Institute, CardiffUniversity of Wales Institute, Cardiff

Copyright © Prof Chris Griffith, UWIC2008

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FAO / WHO Pan European Conference on FAO / WHO Pan European Conference on Food Safety February 2002Food Safety February 2002

“Foodborne disease caused by microbiological hazards is a large and growing public health problem”

“Most countries with systems for reporting foodborne disease have documented significant increases”

Copyright © Prof Chris Griffith, UWIC 2008

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Surfaces:Microorganisms,Cleaning Surfaces:Microorganisms,Cleaning and The Food Processing and The Food Processing

EnvironmentEnvironment

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Transient v Resident PathogensTransient v Resident Pathogens

• Transient– Relatively easily removed by cleaning– Limited amount of product affected

• Resident– Become established, multiply and persist– Significant amount of product affected


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Examples of Lm Plant Persistence by ProductExamples of Lm Plant Persistence by Product

Cheese 11month – 7 years

Fish months – 4 years

Ice cream 7 years

Meat months – 5 years

Poultry 12 years

Tompkin Journal of Food Protection

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Surface Counts and Product Contamination Surface Counts and Product Contamination

• 4 yr Listeria monocytogenes study –JFP 2008

• 46% product isolates and 41% surface

• Persistent strains even after cleaning /dis infection –2 year period

• Strains on gloves /floors


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Maple Leaf Plant Reopens after Listeria Outbreak


• 20 Deaths and estimated Cost of $20 m –Aug /Sept 2008• CEO said the slicing equipment at the plant will now be subject to stricter cleaning and testing , including disassembling

The CEO said the machines had been cleaned on a daily, weekly and monthly basis but it wasn’t until the machines were disassembled that they found the areawhere the bacteria had become embedded

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Surface Counts and Product Contamination!Surface Counts and Product Contamination!

“ SEM showed rods and cocci attached to handling and cleaning tools

Genetically similar strains ( 100%) were isolated from cleaning and handling tools and associated RTE

Transfer of pathogens from cleaning tools to food may hold food safety implications”

Christison et al 2008


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Both are Important BUT

End Product Testing tells you something has gone wrong

Surface testing tells you if something may go wrong

Both tell you something about your systems

Griffith, 2008

End Product and Surface Testing End Product and Surface Testing


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Summary Food IndustrySummary Food Industry

Environmental surface sampling recognised as important. One study suggests if an organism is found in the environment there is a 70% chance of it getting into the food.

IAFP Rome 2007

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In Addition to Food Safety• Pleasant and safe work environment (removes dirt and grease)• Auditor/ customer confidence (promotes favourable image)• Removes bacteria and food on which bacteria grow• Aids pest control (removes food and pests easier to see)• Enables disinfection• Increased product shelf life and equipment performance • Reduction in:

– Food wastage Surface deterioration– Customer complaints Wear and tear– Physical contamination

Other Reasons Why Cleaning is ImportantOther Reasons Why Cleaning is Important


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Cleaning

• Removal of soil

Disinfection

• Destruction or removal of microorganisms

• Aim: to reduce to an acceptable level - little or no risk

Sanitising

• Cleaning process with an additional element of disinfection (detergent / disinfectant)

CleaningCleaning

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• Detects microorganisms and food residues with sufficient sensitivity

• Works equally well on wet and dry surfaces• Repeatable / Reproducible• Easy to use• Rapid• Cheap• Foolproof / recordable

How to Test for Cleanliness:How to Test for Cleanliness:Characteristics of an Ideal MethodCharacteristics of an Ideal Method

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Assessing CleanlinessAssessing Cleanliness

• No ideal method

• Any testing usually better than none but limitations recognised

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“Monitoring cleaning is a vital component of cleaning management”

“In isolation visual assessment is not a good indicator of surface cleanliness”

Griffith, 2005 Handbook of Hygiene Control in the Food Industry

Food Industry PerspectiveFood Industry Perspective


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MicrobiologyMicrobiology

Why is swabbing always used as the reference point?

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MicrobiologyMicrobiology

• No accepted standard / optimum method

• ISO 18593

• Highly variable results

Moore G and Griffith, C.J. (2007) Problems Associated with Traditional Hygiene Swabbing: The Need forStandardisation. Journal of Applied Microbiology; 103: 1090-1103

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ISO 18593 – Surface Sampling TechniquesISO 18593 – Surface Sampling Techniques


• Covers swabbing and contact methods• Swabbing diluent• Clean and disinfect after sampling• Sponges / cloths 100cm2

• Lot of variability allowed

• Low temperature swab transport 1-4C < 24hrs

• Contact plate 4 hours• Results used for “trend analysis”• Use of Rt sampling pattern• Contact plate not recommended for pathogens

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Microbiology: ConsiderationsMicrobiology: Considerations

• Is useful as part of an integrated approach• What do you need to know

– Cleaning or contamination• General contamination: presence/absence of

pathogens• Nature / shape of surface• Direct/ Indirect contact• Care with wetting solution if swabbing

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Non Microbial: Food Component Residues - Non Microbial: Food Component Residues - Sole or CombinationSole or Combination

• ATP

• Protein

• Reducing Sugar

• Other

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Relative Merits of Component ResiduesRelative Merits of Component Residues

• Universality - wide range foods

• Quantity in food

• Sensitivity of Test

• Other– cost – time taken– simplicity

• Horses for courses!

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What is Clean?What is Clean?

• What is acceptable / Fitness for purpose ?

• What is attainable?

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Setting Standards: Why?Setting Standards: Why?

• “Cannot manage what cannot measure”

• Need to know where you are

• Benchmarking

• Scientific approach


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What is Acceptable?What is Acceptable?

• USDA <5cfu / cm2

• SFSA Target 1cfu / cm2

Max 3cfu / cm2

• EU / UK Meat legislation <10cfu / cm2

1cfu / cm2 Enterobacteriaceae


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What is Attainable?What is Attainable?

ProductPass Count Fail

Dairy and other <150 151-299 >300

high risk

Raw meat <1000 1001-1999 >2000

Cooked meat <250 251-499 >500

Convenience RTM <300 301-599 >300

Veg / high risk <250 251-499 >500


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Mean and Range ATP for Named Food SitesMean and Range ATP for Named Food Sites

Site Mean ATP Range ATP

Tap Handle 9,821 182 to 145,143

Equipment Handle 37,032 2,756 to 150,00

Bin Lid 15,433 25 to 500,000


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Range Micro Counts for Named SitesRange Micro Counts for Named Sites

Site Minimum Maximum

Tap Handle <2.5 cfu/cm2 100 cfu/cm2

Equipment <2.5 cfu/cm2 >250 cfu/cm2

Handle

Bin Lid 2.5 cfu/cm2 >250 cfu/cm2


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Assessing CleanlinessAssessing Cleanliness

• Integrated approach for maximum benefit

• Selection based on:– Risk– Soil types– Microbial load– Cleaning method

• Assessment– consider failure costs as well as implementation costs

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Choosing a Luminometer Choosing a Luminometer


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Choosing a Luminometer : Considerations Choosing a Luminometer : Considerations

• Sensitivity/ limits of detection

• Repeatability and Reproducibilty

• Other –ease of use ,technical support,reliability

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Choosing a LuminometerChoosing a Luminometer

• Electronics –PMT/photodiode

• Extractant—microbial cells

• Reagents and background levels

• Lab : Field Trials

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• In addition to managing cleaning testing useful in:

Outbreak investigation Identification of reservoirs Benchmarking Education Cost efficiency and financial management Risk Assessment

Other Reasons for Testing Cleaning Other Reasons for Testing Cleaning EffectivenessEffectiveness

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• Presence of pathogens in vicinity of RTE represents significant risk

• Outbreaks linked to poor cleaning and prosecution

• Environmental sampling provides indication of cleaning efficacy

• Provides early warning of possible problems

Summary 1Summary 1


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Summary 2Summary 2

• Assessing cleanliness valuable in Management• Cleaning validation, monitoring and verification

• Variety of test methods• Integrated Strategy: micro and non-micro• ATP valuable rapid technique• Not all Luminometers the same –proper evaluation needed

• Use as part of a Coherent protocol


Documents

UWIC Managing Cleaning :Validation, Monitoring and Verification of Cleaning Programmes Prof Chris Griffith Food Research and Consultancy Unit University