8 replies to this topic

[SpursGirl]

Hi


My manufacturing plant produces ready to eat, pre-packed salad items for retail sale and I have chlorine washing as a CCP as part of my HACCP plan. The chlorine solution is made up in a eurobin and produce items dipped into the bin - no continuous circulation or automatic dosing. The cholorine solution was made up first thing per shift but may only be used for 20 minutes and then not again for maybe 2 hours, and so on throughout the 8 hour shift.We only ran for 8 hours a day.

The CCP is correct chlorine levels in the wash water and critical limits are in place for upper and lower limits. Any out of specification results in a new chlorine solution being made and potential call back of washed material for re-washing since last good check. All pretty standard stuff. My issue is the frequency of monitoring for the CCP. We are a very new factory (<1 year) and the frequency was every new batch of chlorine solution made and re-check before using existing solution due to the small volumes of material and long strtches of non use. In reality only the new batch at the start of the shift was checked. We are now much busier and now run 2 back to back 8 hour shifts (ie 16 hours a day) and the volume being washed has also increased.
I am wanting to move the frequency of chlorine strength checks to every 4 hours but I have had massive lash back from the production manager who is not wanting to do chlorine checks more than once a shif withtout data to support that checks need to be done more frequently. I really do not understand his arguement but his arguement to me is that I have just randomly picked 4 hours without any reasoning behind it. I have explained that this is a sensible frequency and that it would limit the volume to be called back should the chlorine be out of spec, and also that it is impossible to predict the rate of chlorine usage as this would depend upon volume and initial bio-load of the product - so that a batch may be in spec for 7 hours on one day but only 3 hours the next. He has no expereince of working in the chilled food industry and certainly never worked in a factory where washing is performed and he is challenging me to prove why I need the checks performed every 4 hours. Obviously it can be performed less frequently as long as the corrective action is performed should the chlorine be out of spec - but as the material could be packed and sent out to DC by the time we rechecked I do not feel that this is sensible. The other opinion is that all the extra checks involved would mean an increase in labour - i really do not see how and extra 2 chlorine checks per shift (titration method) would blow the labour efficiency!

I cannot get my point across and was wondering if any of you guys out there can help me formulate an articulate and reasoned statement to get the understanding across.Or am I being too rigid and should I let the once a shift (every 8 hours) checking be the agreed frequency?

Many thanks.


S

[Charles.C]

Dear SpursGirl,

Not my direct product area but can make a few comments –

1. Based on yr comments, the fundamental problem seems to be no data. You didn’t mention the product or crit.limits or prevailing control success so slightly difficult to interpret the situation. Must say that unless yr sampling is significantly interfering with the process flow, i don't quite see why the Prod.Mngr should care one way or the other. Unless there is a known problem . One typical solution is to compromise on a short trial period to simply acquire some data so as to justify (or not) anything further. Seems at the moment you have no idea of the variance. There is another old thread here regarding a similar process but in an external environment, ie probably dirtier product and a lot more throughput than present case, it was surprising how quickly the chlorine level dropped when product passed through the washing step. The theory (as I’m sure you are aware) is that the real control is simply to maintain a clean water supply, bactericidal effects at the best being in the 0-2 log range. However there are some magic chemicals around these days which do have some higher bactericidal efficiency. And also a lot of fakes I believe.

2. Corrective actions can be avoided via setting appropriate “operational limits” as a precaution but this is tricky if the variance is swinging up and down, or simply high. Often a case of trial and error based on process data.

3. You are maybe lucky yr Prodn Manager didn’t challenge this as a CCP, it is debatable unless “validatable” or legislatory. Have read many textbook arguments over this case. Nonetheless there are several published examples of a CCP with “typical” critical limits / monitoring frequencies. Some use automatic analysis/feedback dosing which avoids the sampling problem altogether (at least in theory anyway). At a cost of course.

4. Yr argument over the recall aspect is understandable but it’s surprising IMEX how many processors take such “pragmatic” gambles, even on micro.criteria. The usual defence / safety net is to validate that any “shipped” lot is still in returnable 1st stage transit within the analytical results time scale. From a QA (and one would hv thought an auditor also) POV, clearly not positive release but it is still done. Clearly some data should allow an estimate of the level of gamble involved.

Rgds / Charles.C

[Snookie]

I also do produce in all of its varieties and for some time, including lettuce. Generally we check hourly whether it is chlorine or other washes. Chemical strength can drop quickly depending on load. We want don't want to rewash due to production and labor costs and it is very hard on some commodities such as lettuce and will significantly impact shelf life. Not such a problem if your product is going to be eaten right away, however if you want anything beyond 7 days, you don't want to rewash.


I totally agree with Charles on point # 3 and is such a sensible thougtht. However for many us customers are the driving force, quite simply they want it as a CCP.

[SpursGirl]

Thanks Charles and snookie!

I guess for me the issue is that we are not adequately controlling a CCP as the current frequency of monitoring is not sufficient - in my mind- to demonstrate operation within critical limits. The washing is for leaf and produce and is used in products that have up to 10 days life. I know from experience that chlorine levels drop rapidly and this is why I would like the checks more frequently to avoid re-washing. To me a test every 4 hours seemed reasonable given our throughput but I was asked to prove that this was indeed necessary and that is where I am struggling. Even if I ran a trial for a few weeks does that actually prove anything?? Dirt and biol-loads will vary between materials and grower to grower so that the rate of chlorine depletion will vary day to day.

I take the point regarding washing as a CCP and I think I would actually find it hard to justify a CCP where monitoring is only once every 8 hours - so maybe that is the answer!! Remove the CCP status and test once per shift 😊

[GMO]

For CCPs, the corrective action needs to be achievable and realistic for your process and that means the amount brought back. Remember the ideal for CCP monitoring is "continuous" so the more frequent the monitoring, generally the better.

I have worked with vegetable washing systems before though and this is a very long time to be keeping the same wash solution. Many have continuously replenishing systems built in. From my reading up on the subject, it seemed to be that the chlorine in the wash water does nothing to reduce loading on the leaves; however, the water quickly becomes contaminated and what the chlorine does is reduce the loading in the water. I suspect on at least some days you are doing more contaminating with that was water than you are cleaning!

This is how I'd approach it. I'd validate the whole process from scratch. This would cost a couple of hundred quid in lab fees and testing so this might not be something you'd want to do depending on the size of your business but I think it would be worth it.

I'd take samples of the wash water at the start of production and test. I'd take a sample of the raw material and the washed raw material i.e. either side of the washing process. Then I'd send them off for testing, probably for TVC, Listeria and coliforms? I'd then repeat this process every hour. I'd repeat this for, say, two more days (not consecutive, ideally at least one of them should be a hot day so the loading is likely to be high in the water). You could also take samples of the wash water for micro testing but in some ways all you're interested in is the loading of the vegetables not whether the water is capturing that loading. It's up to you. Remember to put into bottles containing sodium thiosulphate though so it deactivates any residual chorine. I see this as a validation exercise that it is capable of controlling the hazard and also a validation of the water change and test frequency. In which case it is totally worth it. Just keep in mind you may need to revalidate if new pathogens of concern arise.

Also, and I'm harping back a bit here, testing for free chlorine levels and hypochorite or chloride ion levels can give very different results. I can't remember which is the effective thing against the bacteria off the top of my head but you do need to make sure you're checking for the right thing. I heard a story once where a factory ended up adding so much chlorine, the peppers went white!

[isabelle campbell]

As a production manager myself, I quite often come across quality assurance interventions that are based more on gut than on actual fact. I am always asking what the basis for the assessment of risk is. I'm in agreement that to setup proper monitoring controls first you have to understand where and when the risk is. Having a properly researched system of monitoring and control should replace the use of corrective action reporting in determining something has gone wrong.

[frawat]

Hi
Sorry my reply is very late, but just recently my customer is strongly persuading us to put a CCP in our hydro-cooling step. Also, I think this subject is fascinating and it has been a long time since I have participated in the forum.
We do fresh green asparagus, which almost certainly will be cooked before eating.
Of course the hydro-cooling is not meant as a sanitizing or "killing step" step but rather for chilling the asparagus to 2°C. Many people mistakenly consider (or have so) this step as a control to reduce or eliminate potential pathogens in the asparagus, which seems to be silly since the step is not really capable of assuring this. However now we are more conscious about the safety of the cooling or washing water, so we are aware of the importance of keeping enough residual sanitizer in the water, to prevent bacteria build up and potential contamination with pathogens through the water.

What I can comment, and would like to check your opinion, is:

1) If the lettuce comes from the field significantly contaminated with pathogens, no washing with chlorine will eliminate the hazard. So I would say that Good Agricultural Practices and good suppliers is essential.

2) It seems so in your case, but just in case, you have to measure chlorine in the worst scenario and at the outlet (if there is some water renewal).

3) I use peroxiacetic acid instead of chlorine because it is more realiable in keeping concentration and it does not need pH regulation. I have found that we may have pathogen indicator micro-organisms (like E.coli) in the water even though we had some residual sanitizer concentration, so be careful with your limits.

4) I think the HACCP team with the help of an expert (if necessary) should work and validate the risk analysis and the HACCP plan, and not the orders from the production manager (who has all the right to question of course). Authority is different in food safety issues.

Best regards,
Francis

[Charles.C]

Dear Frawat,

Nice to hear from you.

I assume product will not be cooked. if otherwise the argument totally changes of course.

Of course the hydro-cooling is not meant as a sanitizing or "killing step" step but rather for chilling the asparagus to 2°C. Many people mistakenly consider (or have so) this step as a control to reduce or eliminate potential pathogens in the asparagus, which seems to be silly since the step is not really capable of assuring this. However now we are more conscious about the safety of the cooling or washing water, so we are aware of the importance of keeping enough residual sanitizer in the water, to prevent bacteria build up and potential contamination with pathogens through the water.

Your comment regarding mechanism of chlorine effect (essentially preventing cross-contamination) seems well accepted in the literature but whether step is a CCP or not can be a tricky decision. The possibility can depend on the actual process, actual input and interpretation of CCP (ie. the acceptable level for a “safe” final product). The typical published overall bacterial reductions at the “dipping” step for “hypochlorite based systems range maybe up to 10^(2) which is certainly below typical individual cooking “elimination” type reductions (usually >= 10^(5)). However validated combination CCPs which include input load figures have been published (although not many AFAIK ). One might say this is then also an evaluation of the GAP contribution. Also some of the more exotic dipping systems have claimed higher reductions (I think?).

Some haccp users in vegetable product area simply modify the definition of a (Codex) CCP to include "significant" reduction although USFDA seem to have avoided this zig-zag in their own detailed recommendations.

AFAIK, your point No.1 is in agreement with published current Codex viewpoint. Not my field really but I think another vegetable process feature (inc. lettuce?) is that contamination levels may increase substantially at post-harvest manipulation stages such as cutting.

Rgds / Charles.C

[frawat]

Charles,

Thank you very much for your kind and detailed reply.

In the case of fresh asparagus, I do not think it should be a CCP, according to the HACCP approach.
However, some customers (specially from restaurants) are concerned about cross-contamination in the kitchen with other ready to eat food, so they expect the asparagus to be almost free of pathogens.

I think they are also very concerned about recent emerging issues with cantaloupes, etc., so maybe a more proactive approach is necessary.

In the case of ready to eat vegetables or fruits this is different as you say.
And of course I agree with you (specially for fresh cut)in the sense that sanitation and personel hygiene control measures during processing are essential to prevent re-contamination, together with quality (safety)from the farm.

Kind regards,
Francis