The Pipeline and Hazardous Materials Safety Administration (PHMSA) Emergency Response Guidebook is posted at the website http://hazmat.dot.gov/pubs/erg/guidebook.htm.
This guidebook was developed jointly by the U.S. Department of Transportation, Transport Canada, and the Secretariat of Communications and Transportation of Mexico (SCT) 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.
The book is mainly a guide to aid first responders in quickly identifying the specific or generic classification of materials involved in the incident and protecting themselves and the general public.