The use of a synthetic hallucinogenic drug known as “bath salts” has begun to emerge in Canada, raising concern among health and law enforcement officials.

Containers of bath salts sit on a counter at Hemp's Above in Mechanicsburg, Pa., in this January 2011 file photo. (Chris Knight/The Patriot-News/Associated Press)

The powerful white powder is also known by the name mephedrone and is reported to cause anxiety, delusions and dangerously high blood pressure, as well as occasionally violent behaviour.

The drug is popular in England and the U.S. and now is starting to show up in Canada. It can be ordered legally and inexpensively over the internet in the United States.

Sgt. Paul Edwards of the Bangor, Maine, police told CBC News he would never forget when bath salts first showed up in the city. It was April, and he had just pulled over a driver he suspected was driving drunk.

"Basically, she had her rear end up on the … back rest," he said. "Her body was so contorted and writhing she could not, could not stop."

Within weeks, he said, the drug had spread through the city: "We were dealing with this every single day, several times a day."

In Canada, Dr. Margaret Thompson, director of the Ontario Poison Centre, said bath salts are just starting to emerge. She first saw a patient on the drug last summer.

"We probably were seeing them and didn't know what they were, and our usual drug screens were coming back negative, but we still had a feeling the patient was high on something," she said.

The drug is illegal in Canada.

Thompson said there have been reports of people high on the substance in Toronto, central Ontario and Calgary.

She said all varieties of these bath salts are synthetic derivatives of the drug khat, a plant stimulant popular in parts of East African and the Mideast, but their composition can vary.

Violent behaviour

"You think you're getting something that's like khat, and it could be cut with all sorts of other stuff," she said. "It could be one per cent of the active ingredient, but it might be 100 per cent."

Thompson said the drug increases people's heart rate and blood pressure, and it sometimes causes hallucinations, violent behaviour, or seizures.

The drug is among several new synthetic designer drugs sold online or in small shops as actual bath salts or plant food.

They are packaged as “soothing bath salts” to get around U.S. federal laws and are also marketed as plant fertilizer. The drugs are marketed under names such as Cloud 9, Ivory Wave, Vanilla Sky and White Rush and are sold over the counter in states that haven't banned them.