Everyone struggles to understand verification procedures, even experts. The more you find out about it, the less you realise you know. This is not surprising as Principle 6 Verification is perhaps the most complex. (By Anthony Bowmer of RSA Food Safety)
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So where does everyone struggle? I believe there are 4 main areas of concern; they are:
- The need to verify and validate a HACCP plan is not fully understood
- No real understanding of what verification and validation means
- Confusion over the difference between verification and validation
- Mixing up verification and validation with Principle 4 routine monitoring activities.
The first reason I listed, why do we need to verify our HACCP is fairly easy to resolve, but we first need to know what these terms mean. This is best achieved by asking what is it these words are asking us to do.
Verification asks: Is what should be done, getting done?
Validation asks: Is this the right thing to do? Does it still work?
Let’s consider validation practically.
Before you use you HACCP plan for the first time or following a procedural change you must find out if your plan complies with the law and that the measures being used will control all food hazards. This is easy if you have chosen to use SFBB, CookSafe or Safe Catering. In these systems all the controls have been validated by experts in food safety and approved by the food standard agency, i.e. they have done the testing, experimenting, or statistical analysis, that prove the elements of the HACCP plan are working effectively.
If you writing your own HACCP plans it become your responsibility to validate them, let’s see how you could do this through experimentation.
Imagine you run a small restaurant, and make up your own soup in batches, but do not have a blast chiller. You know from your food hygiene course that you need to cool your soups quickly so you cannot continue to allow soups to cool overnight in the kitchen. To ensure the soup cools quickly, you create some rules for your staff to follow.
- Follow cooking times in recipe for the soup.
- Once the soup has been cooked sufficiently, remove from heat and allow to rest (you can do this because whilst the soup is warmer than 63?C it is outside the danger zone).
- Once the soup following stirring drops just below 80?C (temperatures above 80?C can cause serious burns) divide the soup into two cold smaller metallic containers.
- Move the soup out of the warm kitchen into the cooler cellar area.
- Stir soup every 30 minutes with a clean spoon.
- After 4 hours, transfer to fridge.
The controls appear sensible but will they work. It is time to validate the process.
You decide to set up an experiment, using your calibrated digital temperature probe, a watch and graph paper. You will cook the soup as normal, but this time measure the temperature following cooking, resting, then every hour in the cellar and just before you transfer it to the fridge.
Looking at the results you are able to see that the soup was in the optimum temperature growth zone for most harmful bacteria (between 45?C and 20?C) for just over 3 hours. You think this will be good enough but you want to make sure everything will be ok, so you re-run the experiment again but this time you use a homemade clean ice paddle to help stir the soup, (http://www.thekitchn.com/quick-tip-how-to-cool-soup-qui-71109 ) , the soup cools much quicker this time, spending less than 2 hours in the optimum temperature growth zone. You have successfully validated your controls for cooling soup rapidly. Still one step to go, confirm your system with an expert, your local Environmental Health practitioner. You phone her and run your new controls past her. She sounds impressed with the cooling times, but is concerned about cross contamination, how are you ensuring the homemade ice paddle is clean, how are you protecting the soup from environmental dirt in the cellar? You agree a date for her to visit. On her arrival you show her your charts, and run through how contamination is avoided. She is happy with your controls and says she will send you a letter confirming her visit. That’s it you have validated your system for cooling soup, I guess you will what to try it on other foods you bulk cook in advance. Every important – keep the EHP’s letter and your temperature/time charts, these are important document that form part of your food management plan.
There are at least 10 other ways you could have cooled the soup, but this is how you wanted to do it and it worked. That then is initial validation of your system for cooling food rapidly. You still need to verify it; i.e. confirm what should be done, is getting done?
You train all your staff in the new system, and add the key controls to your weekly performance inventory. The system has been running for 3 days and you decided to verify that staff are performing the controls correctly. You observe their practices and tick them off on your inventory, but something is wrong, on 2 occasions staff were too busy to go to the cellar and stir the soup and on one occasion the ice paddle was placed on a beer keg and left there. You have just verified your system is not working as it should. You work with your staff to find a way of overcoming these problems, then set things in motion again. You recheck in two days, and find everything is working as it should, you have verified everything is as it should be.
Verification and validation does not end there but is you want to find out more you will need to go on our CIEH level 3 HACCP course.
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