### Question
How is the "out-of-service order" defined?


### Answer
The term **out-of-service order** is defined in *49 U.S.C. § 5121* as follows -

> a requirement that an aircraft, vessel, motor vehicle, train, railcar, locomotive, other vehicle, transport unit, transport vehicle, freight container, potable tank, or other package not be moved until specified conditions have been met

#### Citation:
  - *49 U.S.C. § 5121*
  - Heading: **SUBTITLE III-GENERAL AND INTERMODAL PROGRAMS > CHAPTER 51-TRANSPORTATION OF HAZARDOUS MATERIAL**

