4 replies to this topic

[jarna]

can someone advise on how validation could be done on purchase of a new dishwash machine

[majoy]

can someone advise on how validation could be done on purchase of a new dishwash machine

Hi.

You may want to try to use thermolabels or paper thermometers to check the dish washer surface temperature.. These self-adhering labels which is activated (change color) when the the right temp is met (>71degC).

http://www.mv.com/ip...s/hlthfood.html

Validation will depend on what is being required in your local or any standards you are following. For some, it is acceptable to just document the temperature of the machine at a frequency as seen in the gauge installed in it. But most auditors, will do an actual test by running a thermolabel on the dishwash machine.

Since your machine is new, i don't think you will have any problems with it any time soon.


Majoy

[GMO]

You could do a micro study. I'd set it up like this:

Take some dirty equipment, swab before and after for (for example), TVC, Enterobacteria, Listeria, Salmonella then use the machine with the correct programme etc and swab extensively afterwards. Your results should then contribute towards proving your machine is effective.

On micro testing validation and verification can get a bit fuzzy but the idea with validation is you're in the design stage and you're doing a lot of micro testing to prove something. Verification is just the occasional swab to check your controls are still working.

The other thing I'd include in a validation is your original design specification, your preassessment prior to delivery and also your chemical choice. Also be very wary as some dishwashers recirculate water. Might be best to not do this unless it's only used for a prewash cycle (especially if you process allergens.)

[Charles.C]

Dear jarna,

As per the previous posts, validation it depends on several factors, some specific to the machine, some to your requirements.

These general refs may be of some interest although all are slightly old -

 dishwashers - Safe Food Australia - Food Safety Standards Guide.pdf   744.42KB   80 downloads
(esp pg 199 et seq.)
 dishwashers - facts_6904520_can-dishwashing-machines-sanitize-dishes_.html   46.62KB   71 downloads
(inc. the 3 links after the text also)
 dishwashers - Standards-Dishwashing.pdf   249.3KB   103 downloads

Rgds / Charles.C

[Slattery]

Hello Jarna,

My company conducts temeprature verification tests for dishwashers in Hospitals and other healthcare facilities in Ireland. Basically the process we use is to place some wireless temeprature sensors in the machines and record the temperatures being recorded over a 30 minute period, usually 5 / 6 washes. The temperatures must reach a certain level for a certain amount of time. Depending on the standard the time / temp will change but we usually test to 82 degrees C for at least a minute.

I wouldn't use dishwasher temperature labels as these label only tell you if a temeprature was reached and not for how long the temeprature was maintained. Also the temperature should not rise above 90 degrees C as above this temeprature "Flash Drying" occurs and bacteria etc can be baked onto the contents of the dishwasher. Dishwasher label will not tell you if the temp went above 90.

Regards,

Stephen