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
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.