Shell eggs (21 CFR 115.50).

Part 115 of Title 21 of the Federal Code of Regulations provides all necessary processing, storage and market food safety rules concerning the eggs (shell eggs as human food).
This Regulation defines that all shell eggs, whether in intrastate or interstate commerce, held for retail distribution shall promptly be placed under refrigeration upon the receipt at a retail establishment, except that, when short delays are unavoidable, the eggs shall be placed under refrigeration, as soon as reasonably possible; and shall be stored and displayed under refrigeration at an ambient temperature not greater than 7.2 degree celsius (45 F) while held at a retail establishment; shell eggs that have been specifically processed to destroy all viable Salmonella shall be exempt from certain requirements as defined in the text.