[blaines]

That's pretty much the point of chain-of-custody systems, because everyone in that supply chain is involved in ensuring that food is safe. Chain of custody systems help identify the error which lead to an incident, and all parties are held accountable for their part in that process. For example:

- The store refrigerators may have lost power. Those products are now waste or potentially hazardous and must be tossed. (Otherwise risky, temperature can be tracked, but in a loss of power scenario is more difficult)

- The delivery truck broke down. Perhaps the temperature in the trailer went above acceptable food safety thresholds.

- The packaging company potentially stored a product outside of the coolers, leading to a food safety hazard.

etc.

[kayfox]

Refrigerator trucks for food and many refrigerators in stores typically have chart recorders (or the digital equivalent) to keep track of historical temperature.

Some transportation companies even upload that to their freight dispatchers in real time.