(a) Each motor vehicle used to transport a package of highway route controlled quantity Class 7 (radioactive) materials (see Sec. 173.403 of this subchapter) must have the required RADIOACTIVE warning placard placed on a square background as described in Sec. 172.527.
(b) A nurse tank, meeting the provisions of Sec. 173.315(m) of this subchapter, is not required to be placarded on an end containing valves, fittings, regulators or gauges when those appurtenances prevent the markings and placard from being properly placed and visible. [Amdt. 172-103, 51 FR 5971, Feb. 18, 1986, as amended by Amdt. 172-143, 60 FR 50305, Sept. 28, 1995]