The Houston City Council passed a sweeping ban on synthetic marijuana Wednesday, outlawing the sale and use of the designer drug sometimes referred to as kush and hoping to choke off its supply by targeting the way the product is marketed and labeled.

Police have struggled to enforce a 2011 state law against the product - often labeled "potpourri" or "herbal incense" - because that law targets the products' chemical makeup, which dealers have tweaked into hundreds of variants to avoid prosecution.

This year alone, said James Miller, head of controlled substances at the Houston Forensic Science Center, the city crime lab has seen 15 different synthetic cannabanoids, only six of which are regulated.

Meanwhile, the federal Drug Enforcement Agency has labeled Houston a key market and source of synthetic marijuana, and local officials, residents and business owners have become alarmed at the unpredictable effects the drug can have on users, many of them homeless residents buying it for as low as $1 from convenience stores.

Miller said the city's forensics lab tests or fields requests from Houston police officers to examine the designer drugs daily, adding what most concerns him is the rapid evolution of the chemicals being sprayed on the plant material, which simply delivers the chemical additives into the user's system. The chemicals, he said, are sophisticated compounds being developed to trigger hallucinations and strong emotions.

Trudy Wollgast has worked at the city's sobering center, an alternative to jail for inebriates, since 2013. Kush users were infrequent and mellow in demeanor when she started, but have become more common, she said, as well as more aggressive and unpredictable. Weekdays see 10 to 15 users, with perhaps 20 to 30 on weekends, she said.

"They're violent, they have uncontrolled outbursts, they have psychotic episodes," she said. "We recently had a 35-year-old male that was relatively healthy smoking kush. We sent him to the hospital because he was complaining of chest pains, shortness of breath; he ended up having a heart attack."

Mayor Annise Parker stressed the drug can cause permanent brain damage and immediate, dramatic behavioral effects

"It is an epidemic," she said. "It is the fastest growing drug of choice across the United States, and it is many, many, many times more potent than natural marijuana and, in fact, it has no relation to marijuana other than it stimulates some of the same receptors in the body. It can cause stupor, but it can also cause aggression and agitation, and it's causing a lot of concern across the community."

Fines can add up fast

Enforcement will begin immediately, with each packet carrying a fine of up to $2,000.

"This will give HPD the tools to go in to the convenience store, the gas station, the smoke shop, wherever it's being sold, and tell the owner, 'Either you get rid of these packages now or we're going to cite you for each and every package,'" City Attorney David Feldman said. "At $2,000 per package, that can get pretty substantial."

Feldman has acknowledged, however, that such bans elsewhere have been difficult to enforce. Nearby cities such as Pearland, Pasadena and La Porte also have targeted kush.

Houston's ordinance makes the synthetic drug illegal in several ways: if the substance is presented as incense but contains ingredients not related to incense; if the packaging implies in writing or the vendor implies verbally that the product mimics the effects of marijuana; or if the packet does not list all the product's active ingredients.

Any officer would be able to walk into a store and cite the owner for displaying kush and seize the drugs if the packages list no ingredients or claim they will get the user high. However, stores likely are violating the ordinance by not publicly displaying the products, Feldman said, meaning undercover police work will be required to examine the packets and prove those violations. Lab testing also would be required to prove the packet contains chemicals that have nothing to do with its advertised use.

Nonetheless, Feldman said many stores will stop carrying the drugs rather than risk thousands of dollars in fines, and said those that persist will be easy targets for police, who already know the problem shops.

"The cops know where this stuff is being sold because it could be legally sold," he said. "I don't see it as being a burdensome effort. You can just target periodically. I suspect you're going to see a concerted effort to do that."

Former users back ban

Former kush users implored council at its public session on Tuesday to pass the ban.

Amanda Howell, now 23 and studying to be a chemical dependency counselor, said she began smoking the drug at 18 and within months was unable to get out of bed or bathe herself. The drug was easier to get than alcohol, she said, and was ubiquitous among her peers.

"This is more dangerous than anything we've seen before," she said, "and people don't even know what it is."

Billy Ford told the council he had smoked only a small amount of kush when he took off running down the middle of a downtown street, where he was clipped by several cars. Friends informed him later of the incident, which sent him to the hospital; he had no memory of the event.

"I smoked marijuana, I smoked crack. There's nothing like kush," he said. "You go downtown right now, there's so many people down there smoking kush. You can buy one for $1. I wish y'all can do something about it."

The City Council passed the ban unanimously and without discussion.

Councilman Jack Christie said, "Ninety percent of the crime in this city has to do with drugs, simple as that.

"It fries their brain to where they're shooting people, driving through their stores in pickup trucks. We've got to stop the chemicals going into these kids' brains, and adults, too."