Controlling Salmonella and Listeria in Low Moisture Food Manufacturing Facilities Frederick Cook DFA Annual Conference April 3, 2013.

Controlling Salmonella and Listeria inLow Moisture Food Manufacturing Facilities

Frederick CookDFA Annual Conference

April 3, 2013

Contamination of Low Moisture Foods

Pathogen Contamination Examples

Raw Grains Spices Seeds Tree Nuts Ground Nuts

Wheat flour Pepper Sesame Almonds PeanutsCookie dough Paprika Sunflower Pistachios Peanut butterCake batter ice cream Oregano Celery Hazelnuts Peanut paste

Pumpkin PecansWalnuts

Low Moisture Foods

Lower moisture can eliminate the ability of pathogenic bacteria to multiply

Not a “Potentially Hazardous Food” (Aw >0.85 and pH >4.6) requiring time/temperature control to prevent growth for safety

But in dry conditions:• Bacteria have increased heat resistance• Bacteria may survive for very long periods of time• Bacteria can transfer and contaminate the product stream

Finished Product Testing for Pathogens

5% of Samples Contaminated 1% of Samples ContaminatedProbability of Probability of Probability of Probability of

nLot Acceptance Lot Rejection Lot Acceptance Lot Rejection

1 0.95 0.05 0.99 0.01 5 0.77 0.23 0.95 0.05 15 0.46 0.54 0.86 0.14 30 0.21 0.79 0.74 0.26 60 0.05 0.95 0.55 0.45300 <0.01 >0.99 0.05 0.95

Source: International Commission on Microbiological Specifications for Food

General Controls for Food Safety in Facilities - Preventive

Food Safety Plan – HACCP based – including validated CCPsPrerequisite Programs

• Raw material control• Pest control• Allergen control• Glass/physical hazard control• Sanitation SOPs• Water control• Personal Hygiene• Environmental contamination control

General Controls for Food Safety in Facilities

Conditions that Allow Multiplication of Pathogenic Bacteria• Food• Acidity• Temperature• Time• Oxygen• Moisture

Exclusion of Moisture will prevent multiplication of pathogens in the food facility and reduce risk of their spread

Water Control

WAR ON WATERTime

Microbial Growth

Food WaterMinimize presence of water by eliminating , reducing

and controlling it wherever possible

Water Control

WAR ON WATER1. Determine areas where water is exposed in the facility2. Map the Facility for Presence of Water / Dry Areas3. Understand why water is used4. Determine strategies for eliminating/reducing/controlling

Necessary Water StrategyProcessing Reduce/controlWet cleaning/sanitizing Eliminate/reduce

Unnecessary Water StrategyCondensation Fix root causeLeaks

Ingress Fix root causeInternal Fix root cause

DrainsBackup Fix root causeLeaks Fix root cause

Water Control

WAR ON WATERMinimize water usage where possibleReduce frequency of cleaning/sanitizing if appropriateEnhance sanitary design (reduce wet time)

Accessible - Cleanable – Sanitizable – Dryable – Inspectable

Substitute dry cleaning/dry sanitizing methods for wet methods and validate them (scrape, brush, vacuum, wipe, alcohol-quat)Visibly clean – ATP standard criteria – Allergen test negatives – APC standard criteria

Enhance water controlPipe directly to drainsEstablish dedicated wash roomsFix leaks / backups

Track water use and water exposure events

Environmental Pathogen Control Program

Prevent transfer of potentially contaminated materials associated with risk to food product safety

• Conduct hazard analysis• Determine boundaries for control• Hygienic Zones different from Product Zones • Establish physical controls• Establish procedural controls

HYGIENIC ZONING

Hazard Analysis – Identify Risks

• Location• Line, process step• Potential contamination type• Origin of potential contamination• Possible Transfer method(s)• Areas that may be affected• Product stream affected• Risk score

Hazard Analysis - Score Risks

• Severity of contamination type• Likelihood of presence• Detectability of presence• Likelihood that product will be contaminated• Detectability of product contamination

Barriers to Sources of Contamination

Barriers to outside sources• Pest control• Security• Physical barrier to water• Physical barrier to air• Physical barrier to other materials

Barriers to Sources of Contamination

Barriers to potentially contaminated materials brought in• Pallets: wooden, plastic• New manufacturing equipment: hygienic condition• Other equipment: hygienic condition• Construction materials: contain• People: captive footwear, uniforms, visitor smocks & shoe cover• Ingredients: sourcing

Employee Entrance

Employee Entrance

Employee Entrance

Hygienic Zones Within the Plant

Barriers to contamination by materials, people, and equipment• GMP Support Zones: employee welfare areas, offices,

maintenance shop, inner docks• GMP Zones

- High Sensitivity GMP Zone: exposed to high sensitivity materials

- General GMP Zone

- High Hygiene GMP Zone: protect post kill product

Hygienic Zone Map of Plant

General GMP Zone

High Sensitivity Zone

High Hygiene Zone

GMP Support

ZoneGMP

Support Zone

Non GMP Zone

Physical & Procedural Barriers Between Hygienic Zones

GMP Support Zone into General GMP Zone• Handwashing

Physical & Procedural Barriers Between Hygienic Zones

Physical & Procedural Barriers Between Hygienic Zones

GMP Support Zone into General GMP Zone• Handwashing• Footwear sanitation

Physical & Procedural Barriers Between Hygienic Zones

Sanitizer Spray Unit for Footwear

23Source:

Physical & Procedural Barriers Between Hygienic Zones

GMP Support Zone into General GMP Zone• Footwear sanitation• Handwashing• Hairnet/beardnet• Safety items: glasses, hearing protection• GMP policies for jewelry, no eating, etc• Illness restriction policy

Physical & Procedural Barriers between Hygienic Zones

High Sensitivity Zones: Contain high sensitivity materials• Walls and doors• Limited access• Air balancing• Hygienic Entrance Area (HEA) – for people• Hygienic Transfer Area (HTA) – for materials and equipment

Example of Hygienic Entrance Area Layout

Hand wash sink

Shoe Sanitize

MirrorBlue

Smocks

Brown Smocks

Supplies

V

TVac Brush Box

High Sensitivity GMP Hygienic Zone

General GMP Hygienic Zone

HEA Procedure – Into High Sensitivity Zone

HEA Procedure – Out of High Sensitivity Zone

Physical & Procedural Barriers between Hygienic Zones

Vacuum Brush Box for Footwear

Physical & Procedural Barriers between Hygienic Zones

Protect High Hygiene Zones to reduce contamination risk• Walls and doors• Limited access• Air balancing• Hygienic Entrance Area (HEA)• Hygienic Transfer Area (HTA)

HEA Procedure – Into High Hygiene Zone

Hygienic Transfer Area Procedure – into High Sensitivity Zone

Hygienic Transfer Area Procedure – out of High Sensitivity Zone

Hygienic Transition Zone (HTA)

Hygienic Transfer Area Procedure – into High Hygiene Zone

Acceptance of Hygienic Zoning Implementation

Safety #1 - committmentCommunicate risk mitigationMinimize costMinimize disruption of manufacturing operationsTraining

Footwear Sanitation – Decontamination Efficacy

Objectives:1. Determine amounts of microbial reduction on footwear

soles using several decontamination treatments.

2. Determine amounts of microbial transfer to floors following various footwear decontamination treatments.

Footwear Sanitation – Decontamination Efficacy

a cb

Pre-treatment boot swabPost-treatment boot swab

R

Slide courtesy Scott Burnett

Footwear Sanitation – Decontamination Efficacy

Reductions on Footwear Soles

5

4

3

2

1

0

0.59, C0.22, C

2.34, B

3.54, A

0.06, C

Aqueous QAC

Dry QAC IPA/QAC IPA/QAC & Dry QAC

No Treatment

Burnett, Egland, McKelvey and Cook, 2013. Food Protection Trends 33:74-81.

IPA/QAC under wet floor conditions

41

6

5

4

3

2

1

0Site ‘b’

IPA QAC

Site ‘b’

None

Site ‘c’

IPA QAC

Site ‘c’

None

Sole

IPA QAC

Sole

None

Burnett, Egland, McKelvey and Cook, 2013. Food Protection Trends 33:74-81.

Footwear Sanitation – Footwear Sanitation

Conclusions:- Aqueous QAC footbath achieved about 0.5 log reduction under conditions of the study.- Nonaqueous IPA-QAC spray achieved > 2.0 log reduction under conditions of the study.- Drawback of dry QAC outweighed the benefit.

Recommendations:- Consider the use of IPA-QAC spray instead of QAC footbath.

• Four times more effective under brief exposure conditions• Reduces water exposure in the facility

Footwear Sanitation – Particulate Pickup and Cleanability

Objective:To classify and determine the ability of various footwear tread

patterns to pick up particulate materials.To evaluate the cleanability of soles having various tread patterns.

Footwear Sanitation – Particulate Pick-up & Cleanability

Wheat berriesCorn gritsRice kernels

Dry and wet floor conditions

Footwear Sanitatioin - Particulate Pick-up & Cleanability

Footwear Sanitation – Particulate Pickup and Cleanability

Conclusions:- Footwear tread patterns can be classified for their ability to pick up particles.- Soles classified as "A" picked up wheat berries, corn grits and rice kernels much less

readily than those classified as "C".- The ability to pick up particles correlates directly with difficulty of particle removal by

brushing or use of a picking tool.- Footwear classified as "C" were much more difficult to clean than those classified as "A".

Recommendations:- Consider the use of “A” soles for enhanced footwear sanitation. This may have benefit for

reducing risks of transfer of potentially contaminated materials within plants, that could pose food safety risk.

Summary

War on WaterHygienic Zoning

Footwear Sanitation

Fred Cook, Ph.D.

Microbiology Fellow

MOM Brands

[email protected]

Thank You!