In the wake of train derailments and a chlorine gas leak
in South Carolina, state and local officials began to examine the scope of their regulatory authority
over the transportation of hazardous materials by rail. Specifically, local officials in the District of
Columbia authorized a temporary ban on the transportation of certain toxic substances from trains
that travel though the District of Columbia. Reviewing the relevant statutes, including the
Hazardous Materials Transportation Act and the Federal Railroad Safety Act, it would appear that
state and local governments are preempted from enacting legislation that would prevent or hinder
the transportation of hazardous materials in interstate commerce. In addition, the Constitution's
dormant, or "negative" Commerce Clause may also prevent a state or locality from imposing such
a restriction as it could arguably be seen as imposing an undue burden on interstate commerce. This
report will provide an overview of the relevant federal statutes with respect to the transportation of
hazardous materials by rail, and will discuss some of the legal issues with respect to both federal
preemption and the dormant commerce clause. In addition, this report will discuss the decision by
the D.C. Circuit Court of Appeals, which, in reversing a district court's opinion, held that the
temporary ban was preempted by federal law and issued a preliminary injunction against its
enforcement. This report will be updated as events warrant.