"Table 1-57: U.S. Hazardous Materials Shipments by Hazard Class, 1997 ",,,,,,,
Hazard class and description,Value      ($ billion),Percent,Tons (millions),Percent,Ton-miles (billions),Percent,Average miles per shipment
Class 1.  Explosives, 4.3 ,0.9%, 1.5 ,0.1%, S , S , 549 
Class 2.  Gases, 40.9 ,8.8%, 115.0 ,7.3%, 21.8 ,8.3%, 66 
Class 3.  Flammable liquids, 335.6 ,72.0%," 1,264.3 ",80.8%, 160.0 ,60.7%, 73 
Class 4.  Flammable solids, 3.9 ,0.8%, 11.8 ,0.8%, 9.6 ,3.6%, 838 
Class 5.  Oxidizers and organic peroxides, 4.5 ,1.0%, 9.2 ,0.6%, 4.5 ,1.7%, 193 
Class 6.  Toxics (poison), 10.1 ,2.2%, 6.4 ,0.4%, 2.8 ,1.1%, 402 
Class 7.  Radioactive materials, 2.7 ,0.6%, 0.9 ,0.1%, RZ , RZ , 445 
Class 8.  Corrosive materials, 40.4 ,8.7%, 91.6 ,5.9%, 41.2 ,15.6%, 201 
Class 9.  Miscellaneous dangerous goods, 23.9 ,5.1%, 65.3 ,4.2%, 22.7 ,8.6%, 323 
Total, 466.4 ,100.0%," 1,565.2 ",100.0%, 263.8 ,100.0%, 113 
KEY:  RZ = less than 1 unit of measure or rounds to zero; S = data were not published because of high sampling variability or other reasons.,,,,,,,
NOTE,,,,,,,
Numbers may not add to totals due to roundings.,,,,,,,
SOURCE,,,,,,,
"U.S. Department of Transportation, Bureau of Transportation Statistics and  U.S. Department of Commerce, Census Bureau, 1997 Economic Census, Transportation, 1997 Commodity Flow Survey, Hazardous Materials (Washington, DC:  December 1999), table 2. ",,,,