A powerful opioid that has a potency that is approximately 10,000 times that of morphine has been found in Toronto for the first time.

Police said that a substance that was seized toward the end of October and was purported to be heroin was recently tested by the Drug Analysis Service Laboratories Regulatory Operations Branch of Health Canada, where it was determined that it was actually a mixture of carfentanil, cocaine and caffeine.

Carfentanil is a more potent type of fentanyl that is used to sedate large animals.

Police say that about 20 micrograms of the drug, which is equivalent in size to a grain of salt, can be enough to kill someone.

“Anytime there is a narcotic that is this toxic it is obviously a public safety concern,” Steve Watts, acting inspector with Toronto police, told CP24 on Wednesday. “If you are a longtime and seasoned user of opioid drugs and you are ingesting a substance of this toxicity there could obviously be some severe and fatal results even with a small dosage.”

The Canada Border Services Agency has made three carfentanil seizures in Western Canada this year, however Watts told CP24 that until recently the closest seizure to Toronto had been in Waterloo.

He said that the arrival of the drug in the GTA is concerning from a public safety perspective, especially given the fact that it was determined to have been laced with other substances.

“That is the issue. It is being cut with other controlled substances and it has no taste or smell,” he said. “So if you cut it with caffeine or cocaine, even a seasoned user would not be able to determine that it had been laced with carfentanil.”

Last week Ontario’s chief coroner said that a total of 165 overdose deaths in the province in 2015 involved fentanyl. Carfentanil is about 100 times more potent than fentanyl.

The Associated Press has previously identified a dozen Chinese businesses that say they will export the extremely potent drug to Canada, the United States, the United Kingdom, France, Germany, Belgium and Australia for as little as US $2,750 a kilogram.