Police and doctors across Canada have been raising the alarm about carfentanil, a drug even more potent than fentanyl.

Carfentanil or carfentanyl (also known as 4-carbomethoxyfentanyl) is an analog of the synthetic opioid analgesic fentanyl. It was found to be four orders of magnitude or 10,000 times more potent than morphine, making it one of the most potent known and the most potent commercially used opioids. Carfentanil was first synthesized in 1974 by a team of chemists at Janssen Pharmaceutica. It is marketed under the trade name Wildnil as a general anaesthetic agent for large animals such as Elephants.

Side effects of fentanyl analogs are similar to those of fentanyl itself, which include itching, nausea and potentially serious respiratory depression, which can be life-threatening. Fentanyl analogs have killed thousands of people throughout the USA since the most recent resurgence in use began in Estonia in the early 2000s, and novel derivatives continue to appear worldwide.

This potent and deadly drug has now surfaced in Canada and is raising alarms with current deaths coming to light.

Dr David Juurlink, head of clinical pharmacology and toxicology at Sunnybrook Health Sciences Centre in Toronto, noted that fentanyl is already arriving in mail packets too small for border agents to inspect, while carfentanil is one-hundred times stronger.

“You can ship a million doses of carfentanil in something the size of a bar of soap. It’s not going to be detected at the borders. We cannot stop these (drugs) from reaching us. And so we have to be prepared to deal with the consequences.”

Juurlink compared carfentanil with a weapon of mass destruction. “If released in a plane or a movie theatre, it would kill a large number pf people. I would not be surprised if, in the years ahead, terrorists got a hold of this stuff,” he said.

It’s heroin laced with elephant tranquilizers, and 100 times more potent than fentanyl. Carfentanil, a new synthetic drug hitting Canadian streets and is causing “mass overdoses.”

Just a few granules of the synthetic opioid are enough to be lethal, drug enforcement officials warn.

Health Canada, for its part, is ramping up efforts to tame the “crisis” it’s seeing within our borders.

“Health Canada is deeply concerned about the growing number of opioid-related overdoses and deaths associated with street drugs, such as illicitly produced fentanyl, as well as pharmaceutical opioids, in British Columbia, as well in other parts of Canada,” the department said in a statement to Global News.

What is carfentanil?

Carfentanil is a synthetic opioid that’s grouped with heroin, fentanyl and oxycodone.

Ingram said that depending on the drug’s purity, carfentanil can be:

• 100 times more potent than fentanyl
• 10,000 times more potent than morphine
• 4,000 times more potent than heroin

“Carfentanil is an analogue of fentanyl with an analgesic potency 10,000 times that of morphine and is used in veterinary practice to immobilize certain large animals,” the U.S. Drug Enforcement Administration says on its website.

“Carfentanil is intended for large-animal use only as its extreme potency makes it inappropriate for use in humans,” the National Library of Medicine explains in its compound summary for the drug.

It looks like table salt, but just a few granules is enough to trigger a fatal overdose, DEA spokesman Russ Baer told TIME.

Frontline emergency responders have to wear gloves and masks to protect themselves from accidentally ingesting even miniscule amounts of the substance.

Just imagine if this drug becomes readily available in all of Canada, the deaths it would cause may be so staggering that it will make the current Canadian Opioid crisis look like a minor incident.