Summary: If you are in possession of halons, you must submit an annual Halon Critical Use return to the Environmental Protection Agency (EPA). You must submit this return for the preceding calendar year between 1st January and 31st March using the online Halon Critical Use Survey Reporting module which is available on the EPA’s EDEN platform. The purpose of this guidance document is to aid these critical users of halons with their submissions through the EPA’s EDEN online platform.