46 CFR § 115.710 - Inspection and testing prior to hot work.
(a) An inspection for flammable or combustible gases must be conducted by a certified marine chemist or other person authorized by the cognizant OCMI in accordance with the provisions of National Fire Protection Association (NFPA) 306, “Control of Gas Hazards on Vessels,” before alterations, repairs, or other operations involving riveting, welding, burning, or other fire producing actions may be made aboard a vessel:
(1) Within or on the boundaries of fuel tanks; or
(2) To pipelines, heating coils, pumps, fittings, or other appurtenances connected to fuel tanks.
(b) An inspection required by paragraph (a) of this section must be conducted as required by this paragraph.
(1) In ports or places in the United States or its territories and possessions, the inspection must be conducted by a marine chemist certificated by the NFPA. However, if the services of a certified marine chemist are not reasonably available, the cognizant OCMI, upon the recommendation of the vessel owner or managing operator, may authorize another person to inspect the vessel. If the inspection indicates that the operations can be undertaken safely, a certificate setting forth this fact in writing must be issued by the certified marine chemist or the authorized person before the work is started. The certificate must include any requirements necessary to reasonably maintain safe conditions in the spaces certified throughout the operation, including any precautions necessary to eliminate or minimize hazards that may be present from protective coatings or residues from cargoes.
(2) When not in a port or place in the United States or its territories and possessions, and when a marine chemist or person authorized by the cognizant OCMI is not reasonably available, the master shall conduct the inspection and enter the results of the inspection in the vessel's logbook.
(c) The owner, managing operator, or master shall obtain a copy of certificates issued by the certified marine chemist or the other person authorized by the cognizant OCMI, and shall ensure that all conditions on the certificates are observed and that the vessel is maintained in a safe condition. The owner, managing operator, or master shall maintain a safe condition on the vessel by requiring full observance, by persons under his or her control, of all requirements listed in the certificate.