A drug that is gaining popularity on the West Coast is moving eastward and is expected to become more of a threat in Maryland, according to a state law enforcement official.

That drug, butane hash oil, is such a concentrated form of marijuana that users have been known to pass out while ingesting it, police said.

"It's what's described to me by one user, 'This is the crack of marijuana,'" said Sgt Mike Conner, who works in the criminal enforcement division with the Maryland State Police. He said it is being seized in Maryland on state highways and through the mail system and "eventually it will come here" on a more widespread basis.

"It's so potent. …. "It's a popular way of people getting a very, very strong high," he said. He said police have also discovered butane hash oil, also known as "dabbing," "honey," "amber," "wax" or "ear wax," being shipped through the postal system to addresses in Maryland, though he said he was unable to specify exact locations. He said drug dealers and users don't know how to extract the powerful oil from marijuana, so they buy it and have it shipped to them.

He cited one traffic stop on I-95 this summer in Cecil County. Police said they seized the oil as well as electronic cigarettes in a vehicle in which passengers were traveling from Florida to New York for a concert.

Users ingest butane hash oil by heating up a piece of metal, like a titanium nail, possibly with a butane torch, and touching the hash oil to it. They then inhale the smoke created from the heat through a glass-smoking device, which, in some cases, can resemble a crack pipe, according to Conner.