For quite a while now while driving, I’ve seen the square “hazard” signs on various tanker trucks and semis. These signs almost always have some number within them, and of course I realize that the numbers have to align with the load/freight that they are carrying.

In my driving boredom I began to wonder about what these numbers represent … time for Google. As I began to search I found a vendor who sells the DOT placards and then a reference to hazardous materials numbering. Well, this second site had an interesting set of pages that allow you to browse through the various numbers and identify the materials. At the bottom of one of them was the quote:

Data Source for our online 2004 ERG

This information was compiled from the 2004 Emergency Response Guidebook (2004 ERG) which is produced by the U.S. Department of Transportation.

Bingo! So the next search for ’emergency response guidebook’ took me to the US Office of Hazardous Materials Safety. And yes … they have a guide book and more! The Emergency Response Guidebook page has a whole slew of formats that you can download the lists of materials … and complete details about their numbering system. They have .PDF versions, and even PDA and PC software versions of their guides. When I didn’t see a Palm version I did a little more searching and found the WISER site. WISER is the Wireless Information System for First Responders, and it has a wide range of tools for looking up the materials, and also looking for how to deal with them. WISER has a Palm version of software I’m going to check out.

After finding what I was looking for, I was amazed at the numbering system, and the details explained in their guidebook … it’s interesting to see the amount of detail that can be extracted by just looking at the patterns of the numbers. (Check out the page numbered 20 in the PDF …)

Well … my driving boredom got me to spend an hour or so to learn something new … and maybe this is a new travel game in the car for vacation trips! “Ok kids … lets see who can find the most variety of hazardous materials between here and St. Louis!” or “Alright, on this part of our trip we want to find the truck carrying the most highly flammable liquid that reacts dangerously with water, emitting flammable gas!”

Uh, that last one would be labeled “X323”, not to be confused with “339” which would be a “highly flammable liquid which can spontaneously lead to violent reaction” … see page 21 in your PDF.