PHMSA produces and distributes the Emergency Response Guidebook (ERG) for use by firefighters, police, and other emergency services personnel who may be the first to arrive at the scene of a transportation incident involving a hazardous material. It is primarily a guide to aid first responders in quickly identifying the specific or generic classification of materials involved in an indicent and protecting themselves and the general public during the initial response phase of an incident. The ERG is updated every three to four yreas to accommodate new products and technology. Part of the update process includes soliciting feedback from stakeholders through a Federal Register notice concerning the necessary updates.