Dishwasher Sanitising Temperatures
Dear All,
We recently had an audit and the auditor came up with a non conformance that the dishwasher final rinse temperature is reaching only 76°C and not 82°C. we had this non conformance continuously flagged up in various audits for past 2 years.
we used different probes, coloured strips and discs before. we contacted the service engineer and he checked with his devices connected to the internal parts of the dishwasher and confirmed that the dishwasher is rinsing at 82°C. The dial is also showing 82°C. Problem is to verify this temperature and to justify the auditors.
I came across the guidance from UK food authority (Attached- page 3) specifying the process of dishwasher rinse that effectively disinfect and not necessarily high temperatures. I heard several companies are struggling to justify this requirement. Could anyone advise if there is any scientific evidence or a notification released in relation to dish washer sanitising temperatures?.
any help is appreciated.
These are the attachments.
Attached Files
Hi vnarla,
I attach the document (pdf) seemingly used to justify the extract posted in yr Post 2. (via the link in yr pdf/Post2 )
thermal-chemical disinfection of equipment with respect to E.coli O157, Campden,2014.pdf 4.15MB 38 downloads
It proposes, inter alia, a thermal best practice -
3.1.5 Overall Thermal treatment best practice:
Thermal treatment best practice:
Hands should be washed prior to cleaning/disinfecting the equipment.
Disassemble the equipment.
Remove all food debris from the food contact item using single use sanitised cloths. Mechanical action and/or chemical treatment (e.g detergent/surfactant) can be applied to help remove any extra food debris.
Parts of the equipment which come into direct contact with food shall be placed into an oven or heated water at temperatures and times shown in Tables 5 and 4 respectively, or equivalent temperatures and times as calculated from wet and dry heat z-values.
The time taken for the surface to come up to temperature must be taken into consideration and added to the total treatment time.
If suitable, instead of using dry or wet heat, a dishwasher at a temperatures of 60°C or higher can be used to clean the food contact items. The time taken for the surface to come up to temperature must be taken into consideration and added to the total treatment time.
The temperature of the surface of the equipment can be verified using temperature indicator strips.
When the surface temperature has been reached, maintain the item at the correspondent time for that temperature.
When the treatment time has been completed, remove the items from the oven or hot water safely and allow to cool on a clean, heat proof surface. Wet items should be air dried or dried with disposable towels.
Once dried or cooled the items should be reassembled with clean hands and moved to a clean area
It appears FSA (and yr auditor) have "interpreted" the caveats in the Campden document in the generation of the quote/Post2. i do not see any data quoted by FSA to justify their specific interpretation.
Basically, from a dishwasher POV, the "thermal efficiency" seems to revolve around come-up time, D-value, adequate time of maintaining utensil temperature. As you noted, further justification/data is required.
Hi,
I have worked with quite a few dishwasher manufacturers over the years, and it is pretty hard to state categorically that a rinse temp is 82 (or not). It seems that you have done some good validations yourself, with test strips, probes and calibrations from the service engineers. I am surprised that your auditor would not accept those records? How did the auditor decide the rinse wasn't up to temp - did they have a thermocouple or a probe? did they sit through a whole cycle with a thermocouple in their hand? I would query the auditor's method and, if necessary their results. Provide the records you have mentioned in your post that support your claim that it is operating at 82 degrees.
Good luck!