EDMONTON - Health Canada says it is moving quickly to include the dangerous synthetic opioid W-18 under the federal Controlled Drug and Substances Act but maintains the drug is already illegal under another law.

The department says it considers W-18, which police say is 100 times more powerful and toxic than fentanyl, to be a new psychoactive substance after testing two samples from Alberta.

The Alberta government has been urging Ottawa to take action after police in Edmonton seized four kilograms of W-18 in December.

Police have said there was enough of the white powdery drug to make millions of pills and Alberta officials sent out a warning to front-line health staff to watch for a possible increase in overdoses.

There were 272 fentanyl-related deaths in Alberta last year and health officials in the province consider W-18 to be more dangerous.

Health Canada says it is moving to treat W-18 as a Schedule 1 drug, which would make its unauthorized use illegal under the Act.