A party to be held in Perth where guests were encouraged to smoke their final stashes of the synthetic cannabis product Kronic has been shut down.

Earlier this week the government announced all synthetic cannabinoids on the market would be banned from Friday, making WA the first state to take such action.

The Kronic Blowout party was planned for Thursday night at the government-funded Perth arts venue The Bakery. A reggae band had been scheduled to play and people were urged to smoke their remaining synthetic cannabis products while they were still legal.

But Health Minister Kim Hames said the party was inappropriate and the arts minister John Day had written a letter to Artrage, the organisation which runs the venue and receives government funding.

"(Mr Day) took the action to send to the director of Artrage a very strong letter which was severely critical of their decision to have a function where people were going to smoke the remnants of this substance," Doctor Hames said.