49 USC 5103 - General regulatory authority

(a) Designating Material as Hazardous.— 
The Secretary shall designate material (including an explosive, radioactive material, infectious substance, flammable or combustible liquid, solid, or gas, toxic, oxidizing, or corrosive material, and compressed gas) or a group or class of material as hazardous when the Secretary determines that transporting the material in commerce in a particular amount and form may pose an unreasonable risk to health and safety or property.
(b) Regulations for Safe Transportation.— 

(1) The Secretary shall prescribe regulations for the safe transportation, including security, of hazardous material in intrastate, interstate, and foreign commerce. The regulations
(A) apply to a person who
(i) transports hazardous material in commerce;
(ii) causes hazardous material to be transported in commerce;
(iii) designs, manufactures, fabricates, inspects, marks, maintains, reconditions, repairs, or tests a package, container, or packaging component that is represented, marked, certified, or sold as qualified for use in transporting hazardous material in commerce;
(iv) prepares or accepts hazardous material for transportation in commerce;
(v) is responsible for the safety of transporting hazardous material in commerce;
(vi) certifies compliance with any requirement under this chapter; or
(vii) misrepresents whether such person is engaged in any activity under clause (i) through (vi); and
(B) shall govern safety aspects, including security, of the transportation of hazardous material the Secretary considers appropriate.
(2) A proceeding to prescribe the regulations must be conducted under section 553 of title 5, including an opportunity for informal oral presentation.
(c) Consultation.— 
When prescribing a security regulation or issuing a security order that affects the safety of the transportation of hazardous material, the Secretary of Homeland Security shall consult with the Secretary of Transportation.
(d) Biennial Report.— 
The Secretary of Transportation shall submit to the Committee on Transportation and Infrastructure of the House of Representatives and the Senate Committee on Commerce, Science, and Transportation a biennial report providing information on whether the Secretary has designated as hazardous materials for purposes of chapter 51 of such title all by-products of the methamphetamine-production process that are known by the Secretary to pose an unreasonable risk to health and safety or property when transported in commerce in a particular amount and form.