Safety-Based Use-By Safety-Based Use-By Date LabelingDate Labeling

Robert L. BuchananRobert L. BuchananDHHS Food & Drug AdministrationDHHS Food & Drug AdministrationCenter for Food Safety & Applied Center for Food Safety & Applied

NutritionNutrition

PresentationPresentation BackgroundBackground NACMCF NACMCF

working groupworking group Subcommittee’s Subcommittee’s

initial thoughtsinitial thoughts Next stepsNext steps

BackgroundBackground Listeria Listeria

monocytogenesmonocytogenes risk assessment risk assessment emphasized the emphasized the importance of importance of the duration and the duration and temperature of temperature of refrigerated refrigerated storagestorage

BackgroundBackground The risk assessessments emphasize The risk assessessments emphasize

thatthat The risk of acquiring foodborne listeriosis The risk of acquiring foodborne listeriosis

is primarily associated with RTE foods that is primarily associated with RTE foods that have high levels of have high levels of L. monocytogenesL. monocytogenes

The risk of foodborne listeriosis is The risk of foodborne listeriosis is generally associated with foods that generally associated with foods that support the growth of support the growth of L. monocytogenesL. monocytogenes at refrigerated temperaturesat refrigerated temperatures

BackgroundBackground Extending period of refrigerated storage Extending period of refrigerated storage

Increases the potential for the growth of Increases the potential for the growth of psychrotrophic pathogenic bacteriapsychrotrophic pathogenic bacteria

Listeria monocytogenesListeria monocytogenes Non-proteolyticNon-proteolytic Clostridium botulinum Clostridium botulinum Yersinia enterocoliticaYersinia enterocolitica Psychrotrophic Psychrotrophic Bacillus cereus Bacillus cereus Others????Others????

Increases the likelihood that the product will Increases the likelihood that the product will be exposed to a period of transitory abusebe exposed to a period of transitory abuse

BackgroundBackground FDA/FSISFDA/FSIS Listeria Listeria

monocytogenesmonocytogenes Action Plan Action Plan Objective #5, Subobjective #3Objective #5, Subobjective #3

FDA and FSIS will seek the advice FDA and FSIS will seek the advice from a scientific advisory from a scientific advisory committee on the scientific basis committee on the scientific basis for establishing safety-bassed “use for establishing safety-bassed “use by” date labeling for refrigerated, by” date labeling for refrigerated, ready-to-eat foods.”ready-to-eat foods.”

National Advisory National Advisory Committee on Committee on

Microbiological Criteria Microbiological Criteria for Foodsfor Foods

NACMCFNACMCF New “Performance Standard” New “Performance Standard”

Working GroupWorking Group

““Requisite Scientific Parameters Requisite Scientific Parameters for Establishing Safety-Based for Establishing Safety-Based Use-By Dates for Refrigerated Use-By Dates for Refrigerated Ready-to-Eat Foods”Ready-to-Eat Foods”

Questions for NACMCFQuestions for NACMCF 1. What are the scientific 1. What are the scientific

parameters for parameters for establishing safety-based establishing safety-based “use by” date labels for “use by” date labels for refrigerated RTE foods?refrigerated RTE foods?

Questions for NACMCFQuestions for NACMCF 2. Should safety-based “use by” 2. Should safety-based “use by”

date labels for refrigerated RTE date labels for refrigerated RTE foods be established using foods be established using mathematical modeling mathematical modeling techniques? If so, what modeling techniques? If so, what modeling approaches are best suited to the approaches are best suited to the development of safety-based development of safety-based “use by” date labels for “use by” date labels for refrigerated RTE foods?refrigerated RTE foods?

Questions for NACMCFQuestions for NACMCF 3. What data needs to be 3. What data needs to be

acquired to scientifically acquired to scientifically validate and verify the validate and verify the adequacy of a proposed adequacy of a proposed safety-based “use by” date safety-based “use by” date label for a refrigerated RTE label for a refrigerated RTE food?food?

Questions for NACMCFQuestions for NACMCF 4. What effect do the multiple factors 4. What effect do the multiple factors

that influence the growth and survival that influence the growth and survival of of L. monocytogenes L. monocytogenes and other and other psychrotrophic pathogens (e.g., strain psychrotrophic pathogens (e.g., strain differences, food matrices, production differences, food matrices, production and distribution systems, consumer and distribution systems, consumer susceptibility) have on the susceptibility) have on the establishment of safety-based “use establishment of safety-based “use by” date labels for refrigerated RTE by” date labels for refrigerated RTE foods?foods?

Questions for NACMCFQuestions for NACMCF 5. What impact would 5. What impact would

safety-based “use by” safety-based “use by” date labels likely have on date labels likely have on the control of other non-the control of other non-psychrotrophic, psychrotrophic, foodborne pathogens in foodborne pathogens in refrigerated RTE foods?refrigerated RTE foods?

NACMCF DLWGNACMCF DLWG

R. Buchanan – R. Buchanan – ChairChair

D. AchesonD. AchesonD. BernardD. BernardC. DonnellyC. DonnellyD. EnglejohnD. EnglejohnS. GarrettS. Garrett

M. KunduruM. Kunduru J. LuchanskyJ. Luchansky M. NeillM. Neill B. SwamanathanB. Swamanathan K. SwansonK. Swanson B. TompkinB. Tompkin

Working Group MembersWorking Group Members

NACMCF DLWGNACMCF DLWG FDA technical FDA technical

liaisons:liaisons: Richard Richard

WhitingWhiting Diana HaoDiana Hao Andreas Andreas

KellerKeller

Date-Label Working Date-Label Working Group: Progress ReportGroup: Progress Report

Scope of ReportScope of Report Identify classes of foods Identify classes of foods

where date labels would where date labels would usefuluseful

Identify scientific parameters Identify scientific parameters to be considered in developing to be considered in developing date labelsdate labels

Recommend approaches and Recommend approaches and requirements for validating requirements for validating date labelsdate labels

Scope of ReportScope of Report Focus on Refrigerated RTE productsFocus on Refrigerated RTE products

that are consumed directly with that are consumed directly with minimal preparation minimal preparation

where the risk of foodborne where the risk of foodborne disease may increase as a result disease may increase as a result of the growth of a psychrotrophic of the growth of a psychrotrophic foodborne pathogen during foodborne pathogen during adequate refrigerated storageadequate refrigerated storage

where date labeling would limit where date labeling would limit the extent of growththe extent of growth

Scope of ReportScope of Report Not covered are:Not covered are:

Foods that do not support the Foods that do not support the growth of psychrotrophic growth of psychrotrophic pathogens of concernpathogens of concern

Foods that remain frozen until Foods that remain frozen until just prior to consumptionjust prior to consumption

Foods that are consumed so Foods that are consumed so quickly after manufacture that a quickly after manufacture that a psychrotrophic pathogen would psychrotrophic pathogen would not have time to initiate growthnot have time to initiate growth

Current Label UsesCurrent Label Uses Most common date label is “sell by” Most common date label is “sell by”

datesdates NIST – Handbook 130NIST – Handbook 130 “… “…(a sell-by date label) allows a (a sell-by date label) allows a

reasonable period after sale for reasonable period after sale for consumption of the food without consumption of the food without physical spoilage, loss of value, or loss physical spoilage, loss of value, or loss of palatability. A reasonable period for of palatability. A reasonable period for consumption shall consist of at least consumption shall consist of at least one third of the approximate total shelf one third of the approximate total shelf life of the perishable food.” life of the perishable food.”

Current Label UsesCurrent Label Uses Currently, variety of other types of Currently, variety of other types of

date labels are used with food productsdate labels are used with food products ““Consume by,” “Best if purchased by,” Consume by,” “Best if purchased by,”

“Best if used by,” etc“Best if used by,” etc These labels are almost always used to These labels are almost always used to

describe product qualitydescribe product quality Focus groups indicate that consumer Focus groups indicate that consumer

interpret them as meaning “Safe to interpret them as meaning “Safe to consume until”consume until”

Current Label UsesCurrent Label Uses There are a few examples There are a few examples

where date labels are used for where date labels are used for safety purposessafety purposes Date marking in Food CodeDate marking in Food Code Use-by dates on infant formula Use-by dates on infant formula

(nutrient loss based)(nutrient loss based)

Label TypesLabel Types Initial thoughts Initial thoughts

is that likely to is that likely to require two require two label systemlabel system Sell-by dateSell-by date Use-within Use-within

instructions instructions from time of from time of purchasepurchase

Factors Affecting GrowthFactors Affecting Growth Primary determinants are the Primary determinants are the

factors that affect growthfactors that affect growth VariedVaried InteractiveInteractive

This information is known, either This information is known, either specifically or generally, for primary specifically or generally, for primary growth determinantsgrowth determinants Temperature ***Temperature *** Water activityWater activity pHpH

Factors Affecting GrowthFactors Affecting Growth One of the key question is what One of the key question is what

temperature should be used to temperature should be used to calculate safety-based use-by calculate safety-based use-by date labelsdate labels Adequate refrigeration (e.g., 4Adequate refrigeration (e.g., 4C)?C)? Marginal abuse (e.g., 10Marginal abuse (e.g., 10C)?C)? Distribution of observed Distribution of observed

temperatures to calculate value temperatures to calculate value of mean + 2SD?of mean + 2SD?

Factors Affecting GrowthFactors Affecting Growth

050

100150200250300350

0 5 10 15Storage Temperature (C)

Tim

e to

3-lo

g In

crea

se

(hr)

Predicted Predicted L. monocytogenesL. monocytogenes growth at growth at pH 6.0, NaCl = 2.5%, NaNOpH 6.0, NaCl = 2.5%, NaNO22 = 20 ppm = 20 ppm

Factors Affecting GrowthFactors Affecting Growth Should the lag phase be Should the lag phase be

included in the calculation of a included in the calculation of a safety-based use-by date safety-based use-by date label?label?

To Lag Phase or Not to Lag To Lag Phase or Not to Lag Phase?Phase?

Lm: 4 C, Lm: 4 C, pH 6.5, pH 6.5, 1% NaCl1% NaCl

Calculated to specified log Calculated to specified log increase (hr)increase (hr)

1 log 1 log 2 log2 log 3 log3 logWith With LagLag

105105 145145 189189

W/O LagW/O Lag 4040 8080 119119% Lag% Lag 62%62% 45%45% 35%35%

Factors Affecting GrowthFactors Affecting Growth Which microorganism?Which microorganism? Which strain?Which strain?

Median?Median? Mean?Mean? Extreme? How extreme?Extreme? How extreme?

Other FactorsOther Factors Target for Label: General Target for Label: General

population? High risk population? High risk population?population?

““Readability” of message?Readability” of message? Seasonal or regional Seasonal or regional

difference? difference? Multiple component foods?Multiple component foods?

DLWG Initial DLWG Initial ThoughtsThoughts

Initial ThoughtsInitial Thoughts Selection of psychrotoph Selection of psychrotoph

establishment of safety-based establishment of safety-based date label: Conduct hazard date label: Conduct hazard analysisanalysis

Use of surrogate possible but Use of surrogate possible but would need to validate against would need to validate against pathogen of concernpathogen of concern

Initial ThoughtsInitial Thoughts Selection of criterion: Selection of criterion: 1 log increase - 10-fold increase in 1 log increase - 10-fold increase in

risk)?risk)? 2-log increase – 100-fold increase 2-log increase – 100-fold increase

in riskin risk Potential for other criteria is can Potential for other criteria is can

assume threshold (e.g., production assume threshold (e.g., production of emetic toxin by psychrotrophic of emetic toxin by psychrotrophic B. cereusB. cereus))

Initial ThoughtsInitial Thoughts Strain selection: Strain that is 2 Strain selection: Strain that is 2

standard deviations above the standard deviations above the mean specific growth rate mean specific growth rate

Pre-adaptation of strains to low Pre-adaptation of strains to low temperature temperature

Use lag phase observed with pre-Use lag phase observed with pre-adapted cells (i.e. minimum lag adapted cells (i.e. minimum lag phase value) unless know source of phase value) unless know source of contamination or previous impact contamination or previous impact of processingof processing

Initial ThoughtsInitial Thoughts Method of inoculation should mimic Method of inoculation should mimic

major mode on contaminationmajor mode on contamination Surface?Surface? Internal?Internal?

Level of inoculation should be as Level of inoculation should be as low as possible while still being low as possible while still being practical and eliminating concerns practical and eliminating concerns about highly variable responses about highly variable responses

Initial ThoughtsInitial Thoughts Inoculated pack studies need Inoculated pack studies need

to be conducted with sufficient to be conducted with sufficient replications to account for replications to account for variabilityvariability PathogenPathogen ProductProduct Processing conditionsProcessing conditions

Initial ThoughtsInitial Thoughts Inoculated pack should be Inoculated pack should be

conducted at two conducted at two temperatures?temperatures? Adequate refrigeration (4Adequate refrigeration (4C)C) 2-standard deviations of 2-standard deviations of

expected distribution of expected distribution of refrigeration conditions (8 to 10 refrigeration conditions (8 to 10 C)C)

Initial ThoughtsInitial Thoughts Likely to use mathematical Likely to use mathematical

models but will have to be models but will have to be careful that are validated or careful that are validated or “fail safe”“fail safe”

Will have to provide “default Will have to provide “default values” for could that do not values” for could that do not have the resources to conduct have the resources to conduct laboratory determinationslaboratory determinations

Next StepsNext Steps

Next StepsNext Steps Revised draft document next Revised draft document next

meeting of the subcommitteemeeting of the subcommittee January, 2003?January, 2003?

Presentation of the most recent Presentation of the most recent draft to full NACMCF committee for draft to full NACMCF committee for commentcomment February/March, 2003February/March, 2003

Completion of documentCompletion of document Late spring 2003?Late spring 2003?

Next StepsNext Steps Interested in Interested in

hearing hearing scientificscientific input and input and identification of identification of pertinent studies pertinent studies or committee or committee reportsreports

Robert.BuchananRobert.Buchanan@cfsan.fda.gov@cfsan.fda.gov