Listeria control guidelines

Control measures for Listeria monocytogenes in ready-to-eat foods

Introduction

What's included

This guidance is based on Health Canada's Policy on Listeriamonocytogenes in Ready-to-Eat Foods and is intended to help food businesses:

• establish control measures to prevent or eliminate the contamination of a food with L.monocytogenes
• determine the RTE risk category for L.monocytogenes
• establish procedures to monitor for the presence of L.monocytogenes in the establishment (environmental sampling program), as well as in RTE food
• determine the actions to take when L.monocytogenes or Listeria species (spp.) is found:
  • on food contact surfaces
  • on non-food contact surfaces
  • in food
• conduct a trend analysis

The examples of control measures for L.monocytogenes are not exhaustive, control measures will depend on the size and complexity of the food operation and be unique for each business.

What's not included

The document does not provide information on how to:

• obtain evidence showing a control measure is effective
• conduct a validation study for the purpose of applying a lower L.monocytogenes RTE risk category
• determine the shelf life of a food

The document does not address labelling requirements specific to RTE food. Labelling information can be found in CFIA's industry labelling tool.

Roles and responsibilities

Food businesses are responsible for complying with the law. They demonstrate compliance by ensuring that the commodities and processes for which they are responsible meet regulatory requirements. If a written preventive control plan (PCP) is required, the food business develops a PCP with supporting documents, monitors and maintains evidence of its implementation, and verifies that all control measures are effective.

The CFIA verifies the compliance of a food business by conducting activities that include inspection, and surveillance. When non-compliance is identified, the CFIA takes appropriate compliance and enforcement actions.

Listeriamonocytogenes in ready-to-eat foods

When conducting a hazard analysis for an RTE food, L.monocytogenes should be identified as a hazard that can present a risk of contamination to the food.

• Identify critical processing steps which may affect the risk classification, such as a lethality step, the use of L.monocytogenes growth inhibitors or pH adjustment
• Identify likely consumers of the RTE food

L.monocytogenes RTE risk category

RTE foods are classified in one of three risk categories based on the health risk L.monocytogenes poses if present in the food. The parameters used to determine the risk category are established in Health Canada's Policy on Listeriamonocytogenes in Ready-to-Eat Foods.

The risk categories are used to determine:

• the control measures and level of monitoring needed to prevent or reduce the risk of contamination of an RTE with L.monocytogenes
• the corrective actions needed to address deviations or inadequate control measures to prevent or reduce the contamination with L.monocytogenes

The following outlines the parameters for determining the L.monocytogenes risk category of a RTE food:

• Category1 product: an RTE food in which the growth of L.monocytogenes can occur
  • This category applies to all RTE food that does not fall in category2A or 2B (below)
• Category2A product: an RTE food in which the growth of L.monocytogenes can occur but is limited to levels no greater than 100CFU/g over the course of the stated shelf-life
  • This category applies to an RTE food that has a refrigerated shelf-life of 5days or less

  Note: If the shelf-life exceeds 5 days, the RTE food could be classified a Category2A product - but only if a validation is conducted and demonstrates that the growth cannot exceed 100CFU/g. The Health Canada documents Validation of ready-to-eat foods for changing the classification of a category1 into a category2A or 2B Food - in relation to Health Canada's Policy on Listeriamonocytogenes in Ready-to-Eat Foods (2011) and Listeriamonocytogenes challenge testing of ready-to-eat refrigerated foods provide information on the validation of the L.monocytogenes RTE risk category.

• Category2B product: a RTE food in which the growth of L.monocytogenes cannot occur over the course of the stated shelf-life.

  This category applies to a RTE food that meets the following parameters:

  • products that are frozen, or
  • have a pH < 4.4 regardless of the aw, or
  • have water activity (aw) < 0.92 regardless of the pH, or
  • have a pH < 5.0 and an aw < 0.94

  Note: If the RTE food doesn't meet the above parameters, it would be classified a Category2B product only if a validation is conducted and demonstrates that the growth of L.monocytogenes cannot occur.

Control measures for L.monocytogenes

The following control measures could be applied to an RTE food to prevent or reduce the growth of L.monocytogenes.

Growth limiting parameters

L.monocytogenes has the ability to grow in an RTE food when the:

• temperature of the food is at -0.4 to 45 °C
• pH of the food is 4.4 or higher
• water activity (aw) is at 0.92 or higher

The pH and water activity (aw) of an RTE food can act as a growth limiting barrier for L.monocytogenes. The product formulation used to prepare an RTE food can be adjusted to bring these parameters to a level that can reduce or eliminate the growth of L.monocytogenes. For example, an RTE food will not support growth of L.monocytogenes when the product formulation results in a:

• pH <4.4 regardless of aw
• aw <0.92 regardless of pH or
• pH and aw factors are combined, for example pH <5.0 and aw <0.94

In order for the growth limiting parameters to be effective, and for the food to remain in the same RTE risk category, the target levels for the parameters have to be met every time the food is prepared and be maintained for the duration of the stated shelf-life. You can ensure this by:

• identifying the processing steps that are essential to achieve the levels needed as critical control points
• setting critical limits for the parameter levels

Note: A change in the product formulation could impact the effectiveness of growth limiting parameters. The new product formulation would need to be validated and the risk category of the RTE food would have to be reviewed.

Food additives and processing aids

Some food additives can inhibit the growth of micro-organisms. The food additives authorized for use as an antimicrobial agent are those found in Health Canada's Lists of permitted food additives. For example, the ClassII preservatives such as potassium lactate, sodium acetate, sodium diacetate and sodium lactate either alone or in combination can be effective in inhibiting the growth of L.monocytogenes.

The use of an antimicrobial additive can affect the categorization of a RTE food under the Health Canada policy. For instance, a Category1 RTE food can become a Category2B when the validation of the antimicrobial agent used demonstrates that the growth of L.monocytogenes does not increase by more than 0.5-logCFU/g for the duration of the shelf-life of the product.

Durable life

The durable life (shelf life) of an RTE food is affected by factors such as the:

• aw
• pH
• microorganisms present on the food
• food additives or processing aids applied
• temperature the food is exposed to during preparation
• post-lethality treatments applied
• storage conditions

The durable life should take into consideration these factors and be limited to the length of time the RTE food can be stored without affecting its quality and safety. The durable life is validated to ensure that the RTE food will remain safe for consumption.

Post lethality treatment

A post-lethality treatment such as surface heat pasteurization (by steam, hot water, radiant heat or infrared technology) and high pressure processing can be applied to the finished RTE food to reduce or eliminate L. monocytogenes that may have contaminated the food after the lethality treatment. These treatments can be used alone or in combination with an approved antimicrobial agent. In the Policy on Listeria monocytogenes in Ready-to-Eat Foods, Health Canada recommends to use a post-lethality treatment that can achieve a minimum 3-log reduction in number of L. monocytogenes.

If the post lethality treatment can achieve a 3-log reduction or more of L. monocytogenes, the recommended sampling frequency can be reduced based on a lower relative risk level (RRL), see Tables 1 to 3.

Limiting exposure to temperatures favorable for L.monocytogenes

When preparing the food, the growth of L.monocytogenes in a RTE food can be reduced by limiting the length of time the ingredients and food are exposed to temperatures optimal for its growth.

The temperature of the area where the food is prepared will determine the maximum length of time that should be taken to prepare a food in order to prevent L.monocytogenes from increasing to a level that can pose a health risk by the end of its shelf life. The food may need to be refrigerated between some preparation steps.

Enhanced sanitation controls

L.monocytogenes is known to form colonies of bacterium (biofilms) that attach to a surface. They are commonly found in niches such as closed systems, areas where moisture accumulates and between close fitting materials. These biofilms are surrounded by a protective sheath of proteins and sugars that make them harder to remove. Basic cleaning and sanitization procedures may not be sufficient for the removal of these biofilms.

The following enhanced sanitation controls are more effective at removing biofilms.

• Using different sanitizers on a rotational basis
  • this prevents the bacteria from becoming resistant to the sanitizer
• Using detergents (such as quaternary ammonium compounds or peracetic acids) combined with mechanical action (such as scrubbing) periodically
  • this improves the removal of proteins, fats, and oils from the equipment and other surfaces
• Following the manufacturer's instructions for the concentrations of sanitizers used and the length of time the sanitizer is left in contact with each surface type in order to achieve proper sanitation
• Sanitizing with high temperatures when the manufacturers' instructions permit such application.
  • hot water and/or steam sanitation is an effective alternative to chemical sanitation and should be used as much as possible as a final step when equipment is difficult to clean
• Designating cleaning equipment such as brushes, scrubbers and carts for use only in specific areas where the risk of L.monocytogenes contamination is the highest
  • this helps ensure that the cleaning equipment does not become a source of contamination by maintaining it in proper condition between uses and by replacing it often
• Cleaning and sanitizing the support equipment such as floor scrubbers, fork lifts, pallet jackets and wheeled trash bins
• Making sure that equipment with removable parts, such as a slicer, is always disassembled and attentively cleaned and sanitized
• Adjusting the frequency of cleaning and sanitizing based on the presence of Listeria species in the areas where food is prepared and/or on equipment used to prepare the food

Monitoring Control Measures

The effectiveness of the control measures applied for L.monocytogenes can be monitored by establishing a sampling and testing program. The document Sampling procedures provides additional guidance that you should consider.

Testing finished RTE food

Testing the finished RTE food for the presence of L.monocytogenes is used to determine whether the controls applied to prevent contamination of the food are effective.

• Obtaining results positive for the presence of L.monocytogenes indicates a loss of control or that the controls applied are not effective
  • such results do not however provide information on the cause or source of contamination, which control measure is ineffective or whether additional measures need to be applied
• The presence and level of L.monocytogenes may differ between units within a lot of RTE food so final product testing for L.monocytogenes should not be your only monitoring or verification activity
  • testing the RTE food is most useful to monitor the effectiveness of control measures applied to the product itself such as growth limiting parameters, additives, lethality treatment and shelf life

Note

Section 7.3 and Table 1: Sampling Methodologies and Compliance Criteria for L.monocytogenes in Ready-to-Eat Foods of Health Canada's Policy on Listeriamonocytogenes in Ready-to-Eat Foods provide guidance on the sampling and compliance levels for each RTE risk category.

Your RTE food sampling and testing program should outline the following:

• The RTE foods tested
• Where the RTE food is to be sampled, and how many sample units are needed for testing
• The sampling materials, methods and procedures
  • use an aseptic sampling technique so as to not contaminate the samples
  • samples should be handled in a sanitary manner and kept at an appropriate temperature before testing to prevent an increase or decrease in the bacterial numbers present in the samples at the time of sampling
    • freezing is undesirable (unless the food is distributed frozen) because it may cause a decrease in the bacterial numbers so the results may not be reflective of the state of the product
    • samples of unfrozen RTE food should be tested within 24 hours of sampling
• How the samples are identified in order to link the test results to the food produced and tested. Samples should be identified using:
  • product name
  • production date or code
  • production lot sampled
• The laboratory where the samples are analysed
  • testing should be done at an accredited laboratory such as a laboratory accredited to the ISO/IEC17025 standard General requirements for the competence of testing and calibration laboratories by the:
    • Standards Council of Canada (SCC) under the Program for Accreditation of Laboratories (PALCAN), in conformity with CAN-P-4D, or
    • Canadian Association for Laboratory Accreditation (CALA)
  • the test should be within the scope of accreditation for the laboratory
• The method used to analyse for L.monocytogenes
  • a recognized test method should be used such as the MFHPB-30 - Isolation of Listeriamonocytogenes and other Listeriaspp. from foods and environmental samples available in Health Canada's Compendium of analytical methods- Volume2
• The sampling frequency for each RTE food
  • take into consideration the level of risk inherent to the food such as its, pH, aw, salt content, the use of antimicrobial agents or a post-lethality treatment

Table 1 presents recommended testing frequencies.

• The use of antimicrobial agents and post-lethality treatments reduces the relative risk level (RRL) of the food and can justify a reduced sampling frequency

Table 1

Product sampling frequency

RTE risk category	Antimicrobial agent used Table Note1	No Post-lethality treatment	Post-lethality treatment Table Note2
Category1	No	Once per month	Once every 6 weeks
Category1	Yes	Once every 6 weeks	Once every 2 months
Category2A	No	Once every 2 months	Once every 3 months
Category2A	Yes	Once every 3 months	Once every 6 months
Category2B	N/A	Once every 6 months	Once per year

Note: Frequencies should be adjusted based on the trend analysis of the results.

For an establishment producing products under different RRLs, the establishment's sampling frequency will be established based on the product with the highest RRL. For a given sampling frequency, higher risk products should be sampled at a proportionally higher rate.

Environmental sampling program

Sampling and testing the areas where the food is prepared, as well as the equipment used to prepare the food, will determine the presence of L.monocytogenes or any Listeria species (spp.). This is important to confirm whether the controls you have applied are effective.

Section 7.2 and figures 1, 2 and 3 of Health Canada's Policy on Listeriamonocytogenes in Ready-to-Eat Foods provides guidance on environmental sampling of both food contact surfaces (FCS) and non-food contact surfaces (NFCS). The MFLP-41- Environmental Sampling for the Detection of Microorganisms method available in Health Canada's Compendium of analytical methods Volume3 provide guidance on sampling materials, procedures, sampling sites and how samples are to be handled and transported.

Your environmental sampling program should outline:

• The sites, for each production line, where the samples are taken based on the process flow chart, traffic flow and critical control points
  • Sampling sites should include both FCS and NFCS identified on a schematic of the process flow for each RTE production line
    • testing NFCS is a valuable tool to detect potential sources of contamination in the establishment before it reaches FCS
    • the sites selected should be reviewed based on the trend analysis of the results compiled
      • Samples should be taken at each production line from at least 10 surfaces that come into contact with the unpackaged food
    • a reduced number of sites could be used if there is a rationale for it (for example, when a RTE food is exposed to the environment only in a very limited number of steps and/or areas)
  • Your process flow diagram can help you identify potential sites of cross contamination between raw and ready-to-eat products or employee flow where a sample should be taken
• The sampling materials, method and procedures used to conduct and collect swabs (such as sterile sponges or cotton swabs) of environmental samples
  • A recognized sampling method should be used such as the MFLP-41- Environmental Sampling for the Detection of Microorganisms method available in Health Canada's Compendium of analytical methods Volume3
  • Use an aseptic sampling technique so as to not contaminate the samples
  • Samples should be handled in a sanitary manner and kept at an appropriate temperature before testing to prevent an increase or decrease in the bacterial numbers present in the samples at the time of sampling
    • freezing is undesirable because it may cause a decrease in the bacterial numbers so the results may not be reflective of the state of the environment
  • Samples should be collected during production, typically after 3hours following startup
    • Samples can also be collected before the start of operations to focus on the effectiveness of the cleaning and sanitation procedures applied at the end of a shift
  • Up to 10 samples of the same type (FCS or NFCS), from different sites, may be combined and tested as one composite sample (if this method is validated to be effective)
  • Samples should be tested within 24 hours of sampling
• How the samples are identified so that the test results can be linked to the sites tested. Samples should be identified using sampling location, time and date of sampling
• The target organism to be analyzed (Listeria spp. or L.monocytogenes).
  • Monitoring the presence of all Listeria spp. in the environment may provide a better indication of the effectiveness of the control measures than testing only for L.monocytogenes
• The analysis method.
  • A method published in the Health Canada's in Health Canada's Compendium of Analytical Methods Volume 3 for Listeria, in which the "application" section is appropriate for the intended purpose (such as MFHPB-methods and MFLP-methods), should be used
• The laboratory where the samples are analysed
  • Testing should be done at an accredited laboratory such as a laboratory accredited to the ISO/IEC17025 standard General requirements for the competence of testing and calibration laboratories such as the Standards Council of Canada (SCC) under the Program for Accreditation of Laboratories (PALCAN), in conformity with CAN-P-4D or the Canadian Association for Laboratory Accreditation (CALA)
    • The test should be within the scope of accreditation for an accredited laboratory
  • The analysis of NFCS samples can be done in-house or by any laboratory
• The sampling frequency
  • The testing frequency should be based on:
    • The RTE risk category of the food. If preparing foods of different risk categories, the sampling frequency should be based on the highest risk category
    • The potential for product contamination. For instance, the environment of the establishment could be divided into zones that are defined by the proximity of the NFCS to the exposed food. ­
      • The areas, zones or levels immediately adjacent or in close proximity to the exposed food, or FCS, would be a higher priority for environmental sampling than those further from the exposed food, or FCS, and those in a non-food processing part of the establishment
    • A trend analysis of the results compiled
  • The testing frequency and the sample sites should be increased when there are situations that can compromise the controls for Listeria such as:
    • construction
    • the installation of previously used or modified equipment
    • an unusual weather event

Table 2 presents FCS testing frequencies when preparing the highest risk Category 1 RTE food.

Table 2

FCS testing frequency per production line according to the relative risk level for the highest risk Category 1 RTE foods: Deli meat products Table Note1, Hot-dogs, smoked seafood and cooked ready to eat crustaceans Table Note2

Production volume Table Note3	No antimicrobial agent or post-lethality treatment	Antimicrobial agent Table Note4	Post-lethality treatmentTable Note5	Antimicrobial agent and post-lethality treatment
Very small	Once per month	Once every 2 months	Once every 2 months	Once every 3 months
Small	Twice per month	Once per month	Once per month	Once every 2 months
Medium	3 times per month	3 times every 2 months	3 times every 2 months	Once per month
Large	4 times per month	Twice per month	Twice per month	Once per month

Table 3 presents FCS testing frequencies generally recommended.

• The use of antimicrobial agents and post-lethality treatments reduces the relative risk level (RRL) of the food and can justify a reduced sampling frequency

Table 3

FCS testing frequency per production line according to relative risk level (RRL) for RTE foods not covered by Table 2

RTE risk category	Antimicrobial agent used Table Note1	Post-lethality treatment not applied	Post-lethality treatment is applied Table Note2
Category 1	No	Once per month	Once every 2 months
Category 1	Yes	Once every 2 months	Once every 3 months
Category 2A	No	Once every 3 months	Once every 6 months
Category 2A	Yes	Once every 6 months	Once per year
Category 2B	N/A	Once every 6 months	Once per year

Follow-up procedures

Follow-up procedures are set out in Figures 1, 2 and 3 of Health Canada's Policy on Listeriamonocytogenes in Ready-to-Eat Foods. These procedures include taking corrective actions as soon as possible when an environmental or RTE food sample is found to be unsatisfactory.

You can determine in advance, and describe in your PCP, the corrective actions you would take when there are unsatisfactory results. They should include:

• actions to be taken on foods that were prepared on the production lines found positive for Listeria
• corrective actions to be taken when L.monocytogenes or Listeria is detected on a sample
• follow-up activities to verify the effectiveness of the corrective actions taken
• activities to address persistent contamination
• procedures to notify the CFIA of unsatisfactory RTE food results if there a risk of injury to human health

Unsatisfactory Food Contact Surface samples

The following are examples of appropriate corrective actions after the initial finding of Listeria:

• Intensifying and increasing the cleaning and sanitation of the equipment and the processing environment
• Completely disassembling the equipment before cleaning
• Addressing equipment or facility design flaws that may be an obstruction and not allow for an adequate cleaning and sanitation, if identified
• Consulting with your chemical supplier to determine if the chemicals being used are appropriate (concentration, contact time, water temperature) and which alternate sanitizers may be applied
• Determining through observations and/or employee interviews whether sanitation and operations procedures are being adhered to, and, if not, correct the situation
• Reviewing the process flow and plant floor diagram to ensure that the potential for cross-contamination is controlled
• Reviewing sanitary control measures to prevent cross-contamination (for example the restrictions of employees flow or establishment of sanitary zones)
• Verify the effectiveness of corrective actions taken
  • Take follow-up samples from the same FCS as soon as possible after Listeria is detected (the samples should be tested individually (no composite)

Persistent contamination

If two or more FCS samples from the same production line are found positive for Listeria within a short timeframe, this is considered persistent contamination and an indication that the sanitation procedures or Listeria control measures are inadequate.

Implement additional intensified corrective actions such as:

• Reviewing the sanitation program to determine if anything has changed, such as new staff, different cleaning chemicals or new cleaning equipment being used
• Doing on-site observations of cleaning and sanitizing procedures, with particular attention to areas identified as positive for Listeria. Observing:
  • what cleaning tools/equipment are being used
  • whether cleaning tools/equipment are being used appropriately
  • whether written procedures are being followed
  • whether the chemicals identified in the written plan are being used
  • whether cleaning chemicals are mixed properly and applied according to the manufacturer's instructions
• Talking with the sanitation crew
  • Do they have any ideas on what may be resulting in the contamination?
  • Have they noticed anything different?
  • Has there been a change in shift or members of the crew?
• Reviewing controls for incoming ingredients and materials and the process flow for sources of cross-contamination
• Reviewing the equipment design
• Reviewing the sampling and testing program
  • Does the sampling frequency need to be increased?
  • Are the sampling sites adequate?
  • Do the sampling programs need to be updated?
• Reviewing previous weekly and monthly results for both the food and environmental samples
  • Are there any trends that could identify a possible source or reason for positive result(s)?
• Looking back
  • Has this happened before?
  • Where?
  • When?
  • What was the cause?
  • How was it fixed?
• Identifying the foods that may be affected?
  • How many days of production since the last negative result?
  • What is the status on inventory and product distribution for the production period in question?
  • What is the shipping information for traceability of affected product?
• Verify the effectiveness of the additional corrective actions taken

Unsatisfactory non-Food Contact Surface samples

Follow-up procedures are set out in Figure 3: Sampling for NFCS especially those in proximity to food contact surfaces (FSC), linked to RTE foods in Category1 and 2, found in Health Canada's Policy on Listeriamonocytogenes in Ready-to-Eat Foods.

The presence of Listeria on NFCS is an indication that improvements are needed to the maintenance and operation of the establishment.

• Corrective actions such as intensive cleaning and sanitation should be implemented immediately and follow-up NFCS taken to verify that they are effective

Follow-up procedures are implemented based on the potential for product contamination taking into consideration surfaces that routinely come in contact with an object that is in direct contact with an exposed RTE food or FCS without a sanitizing step, such as:

• a control panel that is touched by an operator who then handles the exposed food
  • these NFCS present a higher risk of Listeria transmission than other NFCS
  • as a corrective action the operator could replace their gloves prior to contacting the food or FCS

Unsatisfactory RTE food samples

Implement corrective actions immediately when receiving an unsatisfactory RTE food sample results, such as:

• Control and segregate the food that has tested positive and any additional lots of food which may have been implicated (between the time of sampling and the notice of unacceptable results)
• Voluntarily close the establishment or close the RTE line(s) implicated by the unsatisfactory results
• Assess and withdraw from the marketplace any implicated foods that may be in distribution and isolate any returning product
• Review past food testing and FCS sampling results
• Increase and/or enhance cleaning and sanitizing, including equipment disassembly
• Increase employee training
• Extend corrective measures to other foods or processes that may be affected by the problems identified
• Review the sanitation program including the written procedures, the chemicals
• Review sources for raw materials and ingredients, or imported foods
• Review potential cross contamination areas including plant layout, traffic flow, employee practices, equipment design and maintenance procedures
• Review any critical control points and all control measures including critical limits, monitoring and verification procedures; verify processing parameters such as pH, aw, freezing, antimicrobial treatments
• Identify potential methods of disposition of the product
• Sample and test FCS or additional products to:
  • identify gaps in the sanitation program and/or as a verification of the sanitation program's effectiveness
  • determine the source and extent of contamination
  • verify that the corrective actions that have been taken are effective
  • ensure new foods produced on the affected lines are safe before distribution, by implementing hold-and-test procedures

Section 7.3 of the Policy on Listeriamonocytogenes in Ready-to-Eat Foods references hold and test procedures. The same food that was assessed unsatisfactory under the initial sampling plan should be sampled under hold-and-test procedures. If not available, another RTE food (preferably similar) prepared on the affected line can be selected.

Trend analysis

Performing a trend analysis of the test results is an essential component of any sampling program designed to monitor a microbiological risk. Trend analysis allows you to identify a potential loss of control or inadequate controls that can be corrected before they result in non-compliance. For example, corrective measures could be taken when the trend analysis shows that:

• there is a frequent presence of L.monocytogenes at low levels (100CFU/g) in Category2A or 2B products
• there is a high number or increase in unsatisfactory results
• the presence of Listeria migrates from NFCS to FCS

The trend analysis procedures should:

• describe the process followed to review the overall trends which may be identified from sampling and testing results
• identify who will do the analysis
• identify when the analysis will be done
• describe the process followed to review the suitability of the sampling sites, sample numbers and the sampling frequency based on the trend analysis and make adjustments to these or the controls for Listeria

Tell me more! References and further reading

The following references contain information that helps explain food safety controls, demonstrates how to develop them, and provides examples. The CFIA is not responsible for the content of documents that are created by other government agencies or international sources.

CFIA references

• Conducting a hazard analysis
• Critical control points
• Reference database for hazard identification
• Sampling procedures
• Shelf life studies

Other further reading

• Codex Alimentarius, Guidelines on the application of general principles of food hygiene to the control of Listeria monocytogenes in foods, CAC/GL 61-2007
• Health Canada, Canadian standards and guidelines for microbiological safety of foods (Volume1 - The Compendium of Analytical Methods)
• Health Canada, Environmental sampling for the detection of microorganisms - MFLP-41 (2010) (available on request)
• Health Canada, Food Additives that May Currently be Used as Class2 Preservatives to Potentially Control the Growth of Listeria monocytogenes in Ready-to-Eat Foods Sold in Canada
• Health Canada, Guidance Document on Ready-to-Eat Smoked Fish and Multi-Ingredient Products Containing Smoked Fish
• Health Canada, Policy on Listeria monocytogenes in Ready-to-Eat Foods (2011)
• Health Canada, Validation of ready-to-eat foods for changing the classification of a category1 into a category2A or 2B Food - in relation to Health Canada's Policy on Listeria monocytogenes in Ready-to-Eat Foods (2011)

Footnote

Footnote 1

As indicated in Health Canadas policy on Listeria monocytogenes in RTE foods, counts 100 CFU/g detected in category 2 RTE products intended to be produced for high-risk population groups may lead to a higher health risk concern and therefore to an unsatisfactory assessment.

Return to footnote1referrer