The federal Poultry Products Inspection Act (21 U.S.C. § 467e) preempts Webb’s state law claims that Trader Joe’s labels are misleading in stating that they contain less than 5% retained water. Under the PPIS, a poultry products producer must file with the Food Safety and Inspection Service a proposed protocol for measuring retained water. Unless the FSIS objects within 30 days, the protocol is deemed approved. The FSIS must also approve the product labels, including their statement about retained water. Here, Webb’s state law claims were based on measuring retained water by a different means than Trader Joe’s approved protocol, and so imposing that requirement would be an expressly preempted state law requirement “in addition to” the PPSA’s requirements. Also, the PPIA expressly preempted any state law requirement that the product label make a disclosure about retained water that was different from the one which the FSIS had approved.