(a) Chemical testing of personnel must be conducted as required by this subpart and in accordance with the procedures detailed in 49 CFR part 40.

(b) If an individual fails a chemical test for dangerous drugs under this part, the individual will be presumed to be a user of dangerous drugs.

(c) If an individual holding a credential fails a chemical test for dangerous drugs, the individual's employer, prospective employer, or sponsoring organization must report the test results in writing to the nearest Coast Guard Officer in Charge, Marine Inspection (OCMI). The individual must be denied employment as a crewmember or must be removed from duties which directly affect the safe operation of the vessel as soon as practicable and is subject to suspension and revocation proceedings against his or her credential under 46 CFR part 5.

(d) If an individual who does not hold a credential fails a chemical test for dangerous drugs, the individual shall be denied employment as a crewmember or removed from duties which directly affect the safe operation of the vessel as soon as possible.

(e) An individual who has failed a required chemical test for dangerous drugs may not be re-employed aboard a vessel until the requirements of paragraph (f) of this section and 46 CFR Part 5, if applicable, have been satisfied.

(f) Before an individual who has failed a required chemical test for dangerous drugs may return to work aboard a vessel, the MRO must determine that the individual is drug-free and the risk of subsequent use of dangerous drugs by that person is sufficiently low to justify his or her return to work. In addition, the individual must agree to be subject to increased unannounced testing -