[George Howlett]

Wellsy1, on 05 October 2011 - 02:09 PM, said:

Hi George

Thank you for this work its great however i am a little stuck on the Step 2. When you say put a score in what should it be? The prompts are between 1 - 5 so should each question be scored between 1 - 5? What if you dont know the answer to a question should you leave the score out or go for a mid range score ie 3? your help would be much appricated kind reagrds Karen

Hi Karen
Thanks for the question. You are correct. Many of the questions require a numerical answer, say 1 to 5. The value or expression for each number can be found by hovering your cursor over the cell under the 'ANSWER OPTIONS' column. A box will appear with the list of numbers and their description. These are the cells with the red triangle in the top right hand corner of the cell. Once you know the value you want, simply enter it into the SCORE cell adjacent.

For questions that are not applicable etc you simply enter a value of 0.

If you need more clarification just let me know.

George.

[cazyncymru]

Hi George

I've read the risk assessment with great interest, as i've just had to do microbiological risk assessment for my MSc. There were some very good pointers which i have utelised when designing mine.

Thanks

Caz xx

[George Howlett]

Hi Caz


You're more than welcome. Hope the MSc goes well for you.


George.

[Charles.C]

Dear George,

This is a personal view and I apologise if somewhat tangential to the main line of the thread. I don’t wish to be too negative over MRA but it appears to me that for many people who use HACCP, the quantitative aspects of this subject are about as accessible as a black hole.

I totally agree with yr opening post on this topic that it is difficult (and unfortunately potentially dangerous) to present workable (simple) generic menus for application to specific microbiological situations. But unfortunately that is often exactly what official microbiological specifications, standards, etc are obliged to do.

There are some painful critical surveys of the validity of existing micro.standards which existed at the inception of HACCP’s application. I suspect that many of those standards may well still exist today. Unvalidatable on reasoned expert assessment but unchangeable for fear of the (political?) unknown / non-comprehendable, alternatives.

It seems to me that concepts like FSOs and the like were, a decade ago, seen as as a magic wand to bridge the gap between the QMRAs and, for example, the simplistic but intelligible Codex Tree (and its minute footnotes). But in terms of general food application, the beautiful and valuable microbiological insights involved have IMO never taken off, despite the (rare?) inspired attempts to present the information in common parlance in publications such as the Micro-organisms in Food / ILSI texts. And except where QMRA conclusions led to actual numbers which, even if their basis might be somewhat mystical, could be officially seized upon to escape from situations where the tendency to make everything “Zero tolerant” had caused biological niceties to collide with economic realities. (L.monocytogenes is perhaps the classic example.)

A (very) few locations did embody explicit FSO-type concepts in their official HACCP thinking, eg New Zealand, but I deduce from later publications that this philosophy was subsequently reversed for application of HACCP in the food industry at general manufacturing level.

Similarly, in ISO 22000, the ideas are encouraged, perhaps even promoted, to be applied for Hazard Analysis. I have yet to see a single example of detailed published usage other than the Heggum/milk series which appear to hv not been elsewhere developed in freely accessible media. In fact the tendency has been to go back to “Lowest” Common Denominators such as the Codex Tree, probably because they are relatively easy to (mostly) understand, give rapid, agreed-on answers for many standard situations and, perhaps most of all, are “official”. All very acceptable reasons, particularly from an auditorial perspective.

I applaud development of techniques such as the implementation procedure described in this thread but I fear that widespread usage will be conditional on easily understandable/demonstrable benefits as compared to existing prescriptions. And a change in official thinking.

Rgds / Charles.C

[George Howlett]

Hi Charles.C

Many thanks for your post. I think you have opened up some very important issues regarding MRA. Issues which I believe are overdue for debate within the food safety community. You raise a number of points, so forgive me if I don’t address them in logical sequence.

In regard to the model presented in the thread (and I suspect you already appreciate this) it is important to say that it does not attempt to provide a quantitative risk assessment of microbiological hazards. A proper quantitative risk assessment requires significant resources and tools which are beyond the wherewithal of most food businesses. We will leave this for international agencies,governments and research centres. The model presented is qualitative in nature. Although it uses numbers to represent various answers the output remains qualitative and is ultimately expressed in the form of ‘High’, ‘Medium’ and ‘Low’.

There is always the danger that the development and application of structured models to specific situations may result in unsatisfactory decisions and actions – even when those models are intended to make the subject accessible to a wider community of practitioners. Your opinion on this matter is one I would share.

I would also agree with your historical perspective on QMRA. Starting in the mid-90’s the FAO/WHO published a series of documents dealing with food related risk analysis. This was driven by the General Agreement onTariffs and Trade (GATT) and the establishment of the World Trade Organisation’s (WTO) Agreement on the Application of Sanitary and Phytosanitary Measures (SPS Agreement). This required all countries who signed up to made risk analysis the basis of their local food safety laws. The more cynical members of the audience might suggest that this was driven solely from fear of countries using public health as the basis for an unofficial (and illegal) protectionist economic policy. In any event the result was to place science and risk assessment at the heart of food standards. Recognising that ‘zero tolerance’ in all cases would be as unworkable as it sounds, science would be used to establish an Appropriate Level of Protection (ALOP) for the consumer and everybody would be happy. Countries would be able to trade their goods across boarders and the consumer would be protected. This approach was adopted from that already used at the time for chemical hazards in foods and to take account of the biological nature of these hazards. Following a risk assessment, Food Safety Objectives(FSO) could be set and developed into specific process, product and storage criteria to inform and drive local HACCP systems.

It has always been my opinion that the principles set out in the various FAO/WHO documents on risk analysis and risk assessment are sound, valuable and logical. If followed they can ensure risk assessments whether conducted at a government or local level are consistent in their methodology even when the outputs are of questionable value for HACCP. However as you point out all has not turned out as planned and the example of L.monocytogenes supports this. Microbiological criteria, no matter how well intended, are useless if they cannot in reality be achieved. Situations where containers of food are detained at entry ports because they contain levels of L.monocytogenes illegal in that county but perfectly legal in the country from which they came demonstrates the difficulty.

This, of course, reflects what in my mind is the real issue.That which is ‘safe’ food and that which is ‘legal’. A recent food incident in Europe highlighted how the risk assessment wheel had eventually turned full circle. This incident concerned the removal from the market of a significant quantity of food products containing dioxin levels above that legally allowed. This legal level was determined from the application of risk assessment. However, the international authority concerned conducted a risk assessment and determined there was no measurable risk from consuming the contaminated product – yet the product was recalled anyway. It was safe but not legal. This is where I believe risk assessment has damaged its repetition. The dominance of allergen recalls in contemporary food regulation could arguably be a symptom of the same issue.

Having said all that, in my opinion QMRA’s provides excellent information and data (Hazard characterisations / Exposure assessments) required for informing HACCP studies and should be valued on that basis alone. HACCP is a risk management tool and ultimately depends on quality data where available. The model presented can provide practitioners with a structure within which to work and a tool to drive more informed decisions. It can also help to ensure that all relevant factors are at the very least considered. All prescribed models are in some way deficient by their nature and I believe this holds true for simple models like the codex tree which in my experience breaks down for certain hazards in specific situations. Our objective has to be to improve on these models. Some years ago I did some work on developing a simple model for integrating risk assessment and CCP determination. I will dig this work up and share my thoughts on it with you.

Cheers,

George