Microbiological criteria - an introduction Jens Kirk Andersen The National Food Institute Technical University of Denmark

2DTU Food, Technical University of Denmark No of human cases in Denmark:

3DTU Food, Technical University of Denmark Sampling Testing Made decision on the result

4DTU Food, Technical University of Denmark 4 pages that changed the world: 1997:

5DTU Food, Technical University of Denmark

6 Microbiological Criterion (Codex, 1997) : A criterion defining the acceptability of a product or a food lot, based on the absence or presence, or number of microorganisms including parasites, and/or quantity of their toxins/metabolites, per unit(s) of mass, volume, area or lot

7DTU Food, Technical University of Denmark Microbiological criterium consists of: The microorganism Analytical method Sampling plan Acceptable limit/limits The food for which the criterion applies The place in the food chain where it applies Action on failure to meet the criterion Codex, 1997

8DTU Food, Technical University of Denmark Codex, 1997: Food safety is assured by GHP and HACCP Microbiological criteria should be based on science Developed in a transparent fashion Meet the requirements for fair trade Setting of Microbiological Criteria is a Risk Management task

9DTU Food, Technical University of Denmark Risk Analysis Risk Assessment Risk Management Scientific Independent Unemotional “Ivory tower” Pragmatic Possible Political Policy Take decision

10DTU Food, Technical University of Denmark Application of MC (Codex, 1997) : Where no other more effective tools are available When they are expected to improve the degree of protection offered to the consumer

11DTU Food, Technical University of Denmark Sampling uncertainty “Even if you search you shall not always find”

12DTU Food, Technical University of Denmark Sample size 1% contaminated 5% contaminated 10% contaminated Possibility of accepting a contaminated lot:

13DTU Food, Technical University of Denmark No of samples, to document ”absence” ? Def.: ”prescence below 1% at 95% probability” Bacth sizeNo of sample units 1- 60all

14DTU Food, Technical University of Denmark Guarantee - Zero tolerance? Not possible –We cannot test everything Not realistic –We need to eat Not necessary –Pathogens in low levels may be acceptable

15DTU Food, Technical University of Denmark The purpose of an MC is to reduce the risk of the consumer Step 1: Hygiene-based MC - Hygiene parameter, E. coli, TVC etc. Step 2: Hazard-based MC - Pathogenic microorganisms Step 3: Risk-based MC - Directly (mathematically) related to consumer risk – outcome 3 steps to heaven:

16DTU Food, Technical University of Denmark Proces Hygiene criteria –Hygiene parameters –3-class plans –Reaction: Improvement of hygiene + review of HACCP EU microbiological criteria

17DTU Food, Technical University of Denmark Example: Process hygiene criteria (EU legislation) Food category Micro- organism Sampling planLimits Analytical method Stage where MC applies Action if non- complient ncmM Minced meat Aerobic plate count 525*10 5 5*10 6 ISO 4833 End of manufacture Improvement of GMP + raw materials Entero- bacteriaceae ISO End of manufacture Improvement of GMP + raw materials Mechanically separated meat Aerobic plate count 525*10 5 5*10 6 ISO 4833 End of manufacture Improvement of GMP + raw materials

18DTU Food, Technical University of Denmark EU microbiological criteria Food safety criteria –Pathogenic microorganisms –2-class plans –Dramatic reaction when non-complience: Withdrawal Recall

19DTU Food, Technical University of Denmark Microbiological criteria for RTE foods in which growth of L. monocytogenes will not occur ncmMClass Plan Listeria monocytogenes cfu/g a NA2 b2 b [ a This criterion is based on the use of the ISO method. A 25 g sample unit is taken, diluted in 225 ml and homogenized. Duplicate 1 ml portions of this 1:10 dilution of a 25 g sample unit are divided equally onto three standard agar plates (90 mm diameter) or one big agar plate (140 mm diameter) and plated. Thus, two replicate analytical portions of 0.1 g are plated for each original 25-g sample.] Other methods that provide equivalent sensitivity, reproducibility, and reliability can be employed if they have been appropriately validated. National governments should provide guidance on how samples should be collected and handled, and the degree to which compositing of samples can be employed. [ b This sampling plan would provide 95% confidence that a lot of food containing an average concentration of 93.3 cfu/g and an analytical standard deviation of 0.25 log cfu/g would be detected and rejected based on any of the five samples being positive for L. monocytogenes.]

20DTU Food, Technical University of Denmark Towards a risk-based approach: Work has been going on for several years The risk-based angle is being used increasingly in Codex Food Hygiene Committee

21DTU Food, Technical University of Denmark There must be a link between the level of hazard in a food, and the risk for the consumer Therefore it should be possible to translate the level of protection to a microbiological criterion

22DTU Food, Technical University of Denmark ALOP, the Appropriate Level of Protection: The level of protection deemed appropriate by the Member establishing a sanitary or phytosanitary measure to protect human, animal or plant life or health within its territory (Definition by WTO 1995)

23DTU Food, Technical University of Denmark FSO, Food Safety Objective: The maximum frequency and/or concentration of a hazard in a food at the time of consumption that provides or contributes to the appropriate level of protection (ALOP) (Definition: CAC 2007)

24DTU Food, Technical University of Denmark PO, Performance Objective: The maximum frequency and/or concentration of a hazard in a food at a specified step in the food chain before the time of consumption that provides, or contributes to, an FSO or ALOP as appropriate (Definition: CAC 2007)

25DTU Food, Technical University of Denmark The missing link: The transition from Performance Objective to Microbiological Criterion? Two examples on how to do this will be presented at this WG!

26DTU Food, Technical University of Denmark The construction of these parameters form a “cascade” with the ALOP at the top, describing what we are trying to achieve. ALOP Human PO Food Chain FSO Meal/RTE MC

27DTU Food, Technical University of Denmark Alternative approach The principle is simple: 1.Take a sample 2.Do the testing 3.Perform a risk assessment on the result 4.Compare the risk to the average (baseline) risk 5.Acceptability of the food is conditioned on the relative risk An example on this approach is also being presented at this meeting

28DTU Food, Technical University of Denmark Thank you for your attention