Although marijuana remains strictly forbidden by federal law, a federal appeals court ruled Thursday that Congress quietly amended the statute in 2018 to legalize cannabis cigarettes and vaping products that have similar intoxicants but are made from hemp.

The 2018 Farm Bill, signed by President Donald Trump, included provisions removing most legal restrictions on hemp, a cannabis plant with a wide range of uses in industrial products, food, personal care and medicine. The law specified that it did not allow products containing more than a minimal amount of Delta-9 tetrahydrocannabinol, or THC, the active ingredient in marijuana. Although marijuana has been legalized for personal use by adults in California and several other states, and for medical use by many states, it has been banned by federal law since 1937.

On Thursday, however, a conservative panel of the Ninth U.S. Circuit Court of Appeals in San Francisco said the 2018 law had repealed prohibitions on hemp products containing a different cannabinoid, Delta-8 THC.