What written document issued by the regulator authorizes an establishment to modify or waive a food code requirement?

The correct answer is Variance. A variance is a written document issued by the regulatory authority that allows an establishment to deviate from specific food code requirements under certain conditions. This typically happens when a business has demonstrated that it can maintain food safety and public health standards despite not adhering to all existing regulations. When a facility applies for a variance, it must provide justification and, in many cases, a detailed plan on how it will ensure safety and compliance in the absence of the specific regulation. This enables flexibility for unique operations while still safeguarding public health.

In contrast, the other options do not serve the same purpose. An MSDS (Material Safety Data Sheet) provides safety information about hazardous materials but does not relate to food code compliance or modifications. ROP (Reduced Oxygen Packaging) pertains to specific food preparation methods to ensure safety but does not signify authorization to waive food code requirements. A plan review is a process that evaluates the design and operational plans of a food establishment to ensure compliance with safety standards, but it is not a document that modifies or waives food code requirements.