Rules of the Road: CBD no excuse for mariners who fail THC test

Apr 11, 2020 by Capt. Jake DesVergers

In early February, the U.S. Coast Guard issued a Marine Safety Advisory regarding the use of hemp plant products. The advisory was issued to ensure that mariners, employers and associated organizations were aware of certain product ingredients. A number of items marketed as hemp or cannabidiol (CBD) may contain enough tetrahydrocannabinol (THC) to cause a positive drug test. 

In accordance with 46 CFR 16.201(c), an individual who fails a chemical test for dangerous drugs must be removed from duties directly affecting the safe operation of the vessel. The person is also subject to suspension and revocation proceedings against his or her credential under 46 CFR part 5. 

Use of hemp or CBD products is not accepted as an affirmative defense (acceptable excuse) against a THC-positive drug test result. For these reasons, mariners desiring to avoid a positive THC drug test result should exercise extreme caution when considering the use of any hemp or CBD product.  Such use could result in immediate removal from safety sensitive duties aboard a vessel and potential loss of their merchant mariner credential. 

This USCG-issued warning applies to hemp and CBD products in any form, including those that are taken by mouth and those that are applied to the skin. THC is the primary psychoactive component of the cannabis sativa plant. Hemp and marijuana are different strains of the cannabis sativa plant. However, both contain varying concentrations of THC and CBD. 

THC is considered a dangerous drug because it produces an intoxicating effect on the user and poses safety risks to vessel operations. The USCG prohibits the use of THC by mariners because of its known debilitating effect. Any holder of a USCG-issued credential is subject to drug tests that screen for the use of THC. 

Recent changes to federal and state laws have resulted in a surge in the availability of over-the-counter hemp products and CBD products throughout the United States. Hemp products and CBD products are marketed to the general public in several forms, such as food and medicinal products, dietary supplements, oils, cosmetics and hair products. In some cases, product manufacturers market these products as low in THC, or THC-free. 

Mariners should be aware that over-the-counter hemp products and CBD products have not been approved as medications by the U.S. Food and Drug Administration and are not regulated by the FDA. Therefore, users lack federal assurances of their ingredients, THC-content, quality, effectiveness or safe use. As a result, mariners using these products put themselves at risk of having a THC-positive drug test result. It is noted that once THC is in a person’s system, it may remain detectable in urine samples for weeks and hair samples for months after its use is discontinued.

Official policy by the USCG prohibits any mariner or other safety-sensitive operator working aboard a vessel that is subject to federal drug testing regulations to use THC. Claimed use of hemp products or CBD products is not an acceptable defense for a THC-positive drug test result. This also includes any use prescribed by a medical doctor. 

This Marine Safety Advisory is complementary to a previous policy issued by the U.S. Department of Transportation regarding the use of marijuana. Despite growing state legalization and a cultural shift toward greater acceptance of marijuana use, the USCG and the DOT chemical testing continues to identify marijuana as a drug listed on the Schedule I of the Controlled Substances Act. 

Whether the crew member is a green deckhand indulging in recreational use of marijuana in a location where it is legal at the state level or a captain aboard an oceangoing vessel that used legally obtained CBD ointment to treat bodily aches and pains, the resulting positive drug test will lead to the same cascade of negative consequences that can be difficult to overcome. 

Unless and until the drug testing system changes, the best decision a mariner can make is to avoid using marijuana or any products derived from marijuana that may contain THC, such as CBD oil. The threat to a potential accident and risk of career disaster are both too great to take the chance.

Capt. Jake DesVergers is chief surveyor for International Yacht Bureau ( Comments are welcome below.