What are the standards for hood overhang to specific cooking equipment? Is it based on UL Listings of the hood?

The specific overhang (ends, front and/or rear) are predicated on the U.L. 710 testing for the specific model of that manufacturer. When testing for capture of visible cooking vapors, the manufacturer establishes the overhangs to test under (6” (152mm) on the ends for example). Assuming they pass the test, that overhang becomes part of their listing and the installation of that hood has to have a minimum of 6” (152mm) end overhang. You can have greater than the minimum if the application requires that for proper capture and containment. NFPA 96 simply states in Chapter 5.2 Hood Size, “hoods shall be sized and configured to provide for the capture and removal of grease laden vapors.” This coincides with Chapter 8.2.2. on Air Volume which states “Exhaust air volumes for hoods shall be of a sufficient level to provide for capture and removal of grease laden cooking vapors”

International Mechanical Code is more specific to the requirements of overhangs. In the absence of a U.L. Listing for specific overhangs (that has precedent over IMC requirements), Chapter 507.4.1 Canopy size and location calls out for a 6” (152mm) overhang beyond the horizontal distance of not less than 6” beyond the edge of the top horizontal surface of the appliance on all sides. If the hood is listing, the listing overhang applies