Section 153.1025 - Motor fuel antiknock compounds(a) No person may load or carry any other cargo in a containment system approved for motor fuel antiknock compounds containing lead alkyls except a cargo to be used solely in the manufacture of motor fuel antiknock compounds.(b) The master shall ensure that no person enter a pumproom or void space that contains piping from a containment system approved for motor fuel antiknock compounds containing lead alkyls unless: (1) The pumproom or void space atmosphere has been analyzed for its lead (as Pb) content and found to be less than 0.075 mg/m3; or(2) The person follows the procedures for entering a cargo tank described in paragraph (c) of this section.(c) No person may enter a cargo tank endorsed for motor fuel antiknock compounds containing lead alkyls without prior specific authorization from the Commandant (CG-ENG). This authorization may be obtained by calling telephone number 202-372-1420 or e-mail hazmatstandards@uscg.mil if the person has previously obtained approval for the cargo tank entry procedure from the Commandant (CG-ENG).(d) No person may enter a cargo tank endorsed for motor fuel antiknock compounds if he does not follow the conditions in the authorization under paragraph (c) of this section.CGD 73-96, 42 FR 49027, Sept. 26, 1977, as amended by CGD 78-128, 47 FR 21212, May 17, 1982; CGD 82-063b, 48 FR 4782, Feb. 3, 1983; CGD 88-100, 54 FR 40042, Sept. 29, 1989; USCG-2006-25697, 71 FR 55747 , Sept. 25, 2006; USCG-2012-0832, 77 FR 59785 , Oct. 1, 2012