A dangerous drug has arrived in Metro Vancouver, authorities have warned.

Delta Police have said they’ve confirmed the presence of W-18 in drugs seized from three raids conducted on March 17 at locations in Richmond, Burnaby, and Surrey.

“The street level use of drugs like W-18 is still in its infancy in Canada and it appears users are completely unaware of its presence in the drugs they are consuming,” said Delta police chief constable Neil Dubord quoted in a June 7 media release. “It is very apparent to us that drug traffickers are aware of the deadly game they are playing with human lives in the manufacture and sale of these counterfeit drugs. In the seizures done by our investigators, the accused were carefully protecting themselves with respirators, gloves and goggles during the process and yet went on to knowingly sell this product to unsuspecting users.”

W-18 is a synthetic opioid that Health Canada has warned is 100 times more toxic than fentanyl, a similar drug that is largely blamed for a significant increase in overdose deaths in B.C. W-18 was developed in the 1980s as a pain medication but never marketed commercially in Canada. (W-18's status as a synthetic opioid is a matter of debate. Health Canada describes the drug as a synthetic opioid, but David Juurlink, a clinical pharmacology with the University of Toronto, has said the drug's exact classification is "not entirely clear".)

Both W-18 and fentanyl can induce feelings of pleasure similar to the effects of heroin or oxycodone. But they are significantly more potent. That means drug dealers can traffic fentanyl and W-18 in much smaller amounts than heroin, which makes it easier for criminals to evade border controls and law enforcement.

However, the same properties also make these drugs significantly more dangerous than heroin.

“Drug investigators believe that the W-18 was being manufactured to appear like heroin or oxycodone before being sold at the street level," the Delta Police release reads. "For users, this results in a much higher and deadly risk of overdose as they are exposed to a drug they have no tolerance for. In many cases, users are not aware that W-18 (and/or fentanyl) is in the drug that they are consuming. Because the counterfeit heroin and oxycodone are manufactured in clandestine labs, there is no guarantee that the W-18 or fentanyl is evenly distributed or mixed throughout the cutting agent. This causes street users to face potential overdoses from ‘hot spots’ of fentanyl or W-18.”

During the first four months of 2016, there were 256 overdose deaths in B.C., which means there could be somewhere around 768 by the end of this year. That compares to a previous high of 400 deaths recorded in 1998.

During the first three months of 2016, fentanyl was detected in 49 percent of illicit drug-overdose deaths. That’s up from 32 percent in all of 2015, 25 percent in 2014, 15 percent in 2013, and five percent in 2012.

On May 23, the Globe and Mail reported that W-18 was first detected in Western Canada when it was found in the body of a Calgary man who died of a drug overdose in March.

On June 1, Health Canada added W-18 to Schedule 1 of the Controlled Drugs and Substances Act.

The March 17 raids on drug labs across Metro Vancouver were the result of an investigation initiated by Delta Police earlier this year.

According to the release, five people were arrested. Two remain in custody facing more than 20 charges. The other three were released with charges pending.