DOT PLACARDS AND LABELS
DOT Flammable Liquid Placard
Figure 2-3, DOT Flammable Liquid Placard
The Department of Transportation, working with the United Nations, has developed an international classification system for hazardous materials. A substance is classified as hazardous if it “poses an unreasonable risk to public health and safety” when transported. Federal legislation requires that cargo tanks and railroad tank cars, which are carrying regulated hazardous contents between States, bear a four-digit code number (1219). See Figure 2-5 on page 2-9.

This code, called a North American (NA) or United Nations (UN) ID number, is located on placards or panels placed on all four sides of the cargo tank or rail car. If you are concerned about what sort of hazardous materials are passing through your community, you can use these UN ID numbers to categorize the transport vehicles by load. Interpretations of these codes are found in DOT’s Emergency Response Guidebook, which may be obtained through DOT. You can also contact your LEPC to determine the stationary locations of chemicals in your area, and ask the companies involved regarding the origination and destination of chemicals stored there.