just some food for thought----determining shelf life including how it's held at home may be a challenge. It would appear there is a big differance between what the home fridge SHOULD be at and what it IS at
In our study of listeriosis risk factors, we found that although 79% of respondents knew the importance of refrigeration, 84% were unaware that fridges should be 5℃ or less. Furthermore, 65% said they “never check” the temperature of their refrigerator. Later research led us to find that 50-85% of domestic refrigerators were actually operating at higher temperatures than the recommended guidelines, when taking single temperature readings.
We have also looked at how temperature fluctuates in fridges using wireless sensors to track changes on a minute by minute basis over six consecutive days. Surprisingly, we found that no refrigerator was under the recommended 5℃ for the full six days. Around 91% of the fridges had mean temperatures that were higher than the recommended 5℃. Overall, average operating temperatures ranged from -1.7℃ up to 17.9℃. To put that into perspective, the mean temperature for summer 2016 in the UK was 14.9℃.
IIRC, despite a recommended <= 5degC, the legal max. temperature for Fridges in UK is 8degC for the chilled compartment. Studies exist on the "degree" of compliance to such. Curiously there seems no mention of this tolerance in above 2015 UK Link.
I noticed yr fascinating 2006 UK link is "archived". Is it actually current ?
The content is beautifully, repetitively, convoluted IMO. Presumably a fallout from its being a legal entity. Plus, i anticipate, due the inclusion of several intriguingly referenced exceptions. Such as pertaining to the notorious Co-op ambient hotdogs I suspect.
As Tony implied, the methodologies for bestowing labelled shelf lives are subjective and often obscure although scientific analyses/publications do exist (there are many related threads on this Forum). Offhand I think all the publications on shelf life estimation i have seen assume power is maintained. Period.
I think yr query is generally handled in isolation, eg when to reject chilled food after a power failure ?
Officially, I daresay it's highly likely to relate to where you are.
In addition to above info another SOP discussed here several times for chilled failures etc is the 2hour/4hour rule as detailed in various Australian FS publications. You can Google.
IIRC USA/FDA have analogous "dumping" guides to Australia for power failure situations.