Although they did not cite a  specific percentage, they described shipments of undeclared dangerous  goods as “very rare” and “a handful.” The numbers are believed to be  similarly small for the Postal Service—officials estimated that declared  dangerous goods represent less than one-tenth of 1 percent of their  shipments, and the percentage of these shipments that is undeclared is  “very small.” The Volpe Center reported in a 1999 threat assessment that  undeclared dangerous goods shipments made up about 0.05 percent of the  shipments of several large cargo carriers, but this estimate was based on  the recollections of the carriers of how many incidents they typically  report to RSPA. The Postal Service may inspect Parcel Post packages. The Federal Government Depends on Regulations, Research, and Outreach to Prevent Problems

Federal regulations provide a framework for transporting dangerous  goods safely by air. Major Carriers Rely on Known Shipper Policies, Other Restrictions, Training, and Sanctions to Prevent Undeclared Shipments

To prevent undeclared dangerous goods shipments, major carriers limit  their business to known shippers and may impose other restrictions. While the Postal Service cannot limit its business to known shippers, it  accepts fewer dangerous goods for shipment than DOT authorizes to  travel by air. Specifically, by  requiring customers to bring packages that weigh 16 ounces or more to a  post office for shipment, Postal Service employees can inspect packages,  ask questions about their contents to determine whether they contain  anything prohibited, and ensure proper handling for packages containing  dangerous goods that may be mailed. Our analysis of FAA’s enforcement case files  found that FAA is not always documenting its assessments. III for more information about  FAA’s and DOT’s incident and enforcement databases.) Conclusions

Without statistically valid, generalizable data on the nature and frequency  of undeclared dangerous goods in air transport, DOT does not know to  what extent such goods pose a threat to aviation safety, or what resources  should be allocated to address that threat. A change in the law requiring that shippers consent to the inspection of  packages shipped by air might help to accomplish these objectives. However, the distinctions between air and  the other modes that justify more stringent regulations for transporting  dangerous goods by air, along with the potential benefits to aviation safety  that could accrue from better data on undeclared air shipments, might  warrant the development of a proposal that would enable DOT to obtain  such data. Until it fully  documents the reasons for its assessments, or for changes to its initial  assessments, as its guidance requires, it cannot provide assurance that the  penalties are appropriate or that it has handled similar cases consistently. Such a proposal would not only  enhance FAA’s inspection authority but would also enable FAA to obtain  statistically valid, generalizable data on the nature and frequency of  undeclared air shipments of dangerous goods. Scope and Methodology

To determine what DOT, the Postal Service, and others involved in the air  transport of dangerous goods know about undeclared shipments, we  identified relevant studies and interviewed DOT, Postal Service, industry,  and industry association officials. To determine what DOT and the Postal Service do to foster compliance  with federal regulations for shipping dangerous goods by air, we  interviewed agency officials and reviewed reports and documents. These enforcement  data are used to monitor and enforce compliance with DOT’s dangerous  goods regulations.
Why GAO Did This Study

When shipments of dangerous goods (hazardous chemical substances that could endanger public safety or the environment, such as flammable liquids or radioactive materials) are not properly packaged and labeled for air transport, they can pose significant threats because there is little room for error when something goes wrong in flight. To better understand the risks posed by improper ("undeclared") air shipments, we assessed what is known about their nature and frequency, what key mechanisms are in place to prevent their occurrence, and what the Department of Transportation (DOT) and the Postal Service do to enforce federal regulations for shipping dangerous goods by air.

What GAO Found

Little is known about the nature and frequency of undeclared shipments of dangerous goods. While major carriers and the Postal Service believe such shipments are rare, their belief is based mainly on inspections of problem shipments, such as those that leak. Statistically valid, generalizable data are not available and would be difficult to obtain, not only because more inspections would entail costly delays for carriers but also because Constitutional protections limit DOT's and the Postal Service's inspection authority. DOT is seeking greater authority to open potentially problematic shipments for inspection, but its efforts are not limited to air transport and would not enable DOT's Federal Aviation Administration (FAA) to obtain statistically valid, generalizable data on the nature and frequency of undeclared air shipments. A change in the law requiring that shippers consent to the opening of packages for inspection might be appropriate for air transport and would enable FAA to obtain such data. FAA could then identify the resources and actions needed to address the problem. Federal regulations create a framework for transporting dangerous goods safely, and outreach to shippers and carriers helps to prevent undeclared shipments. Private industry does business primarily with "known shippers" (those that have shown they comply with the regulations). The Postal Service cannot restrict its business to known shippers, but it requires customers to bring packages weighing 16 ounces or more to a post office for screening. Carriers and the Postal Service both train their employees to screen for undeclared shipments. The Postal Service and FAA monitor and enforce compliance with federal regulations for transporting dangerous goods by air. However, the Postal Service cannot fine violators and seldom takes criminal action, since most violations are inadvertent. FAA's enforcement guidance calls for documenting the reasons for any changes in the fines its inspectors initially propose. GAO's review of enforcement case files indicates that the reasons for changes were not always documented. FAA attributes some changes to the results of penalty negotiations. Because FAA is not always following its guidance, it cannot ensure that its fines are appropriate or consistent.