I have been asked about the toxic and flammable chemicals that move through town on tank cars. The go-to document is the “2012 Emergency Response Guidebook” published by the U.S. Department of Transportation, Pipeline and Hazardous Materials Safety Administration (co-published by Transport Canada.) It can be downloaded at no cost here: http://phmsa.dot.gov/staticfiles/PHMSA/DownloadableFiles/Files/Hazmat/ERG2012.pdf.
It is a lengthy document (392 pages) but actually quite readable — if you like that kind of thing. It provides guidance on the meaning of the safety placards that we see on tank cars. As time permits I will try and publish a shorter version of this document that we can all use.