Table B-2c. Estimated Standard Errors for Hazardous Material Shipment Characteristics by Hazard Class for the United States: Percentage of Total for 2012 and 2007
(Estimates are based on data from the 2012 and 2007 Commodity Flow Surveys)
Hazard class and description |
Value— standard error |
Tons— standard error |
Ton-miles (1)— standard error |
|||
---|---|---|---|---|---|---|
2012 | 2007 | 2012 | 2007 | 2012 | 2007 | |
Total | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
Class 1, Explosives | 0.2 | 0.2 | Z | 0.0 | 0.1 | 0.0 |
Class 2, Gases | 0.3 | 0.8 | 0.4 | 0.9 | 0.9 | 1.8 |
Class 3, Flammable and combustible liquid | 0.6 | 1.2 | 0.4 | 1.1 | 1.5 | 2.0 |
Class 4, Flammable solid; spontaneously combustible material; dangerous when wet material | Z | 0.1 | 0.1 | 0.2 | 0.5 | 0.3 |
Class 5, Oxidizers and organic peroxides | Z | 0.0 | 0.1 | 0.1 | 0.4 | 0.4 |
Class 6, Toxic materials and infectious substances | 0.1 | 0.4 | 0.1 | 0.1 | 0.2 | 0.4 |
Class 7, Radioactive material | 0.2 | 0.3 | S | 0.0 | Z | 0.0 |
Class 8, Corrosive material | 0.2 | 0.2 | 0.4 | 0.4 | 1.0 | 1.7 |
Class 9, Miscellaneous hazardous material | 0.2 | 0.2 | 0.3 | 0.2 | 0.9 | 0.8 |
KEY: S = Withheld because estimate did not meet publication standards.
Z = Rounds to zero.
(1) Ton-miles estimates are based on estimated distances traveled along a modeled transportation network. See “Mileage Calculations” section for additional information.
NOTES: The Introduction and appendixes give information on confidentiality protection, sampling error, nonsampling error, sample design and definitions. Links to this information on the Internet may be found at <www.census.gov/econ/cfs>.
SOURCE: U.S. Department of Transportation, Bureau of Transportation Statistics and U.S. Department of Commerce, U.S. Census Bureau, 2012 Economic Census: Transportation Commodity Flow Survey, December 2014.