Leading figures in the synthetic cannabis industry are meeting today to discuss ways of reining in their own behaviour to avoid a ban on their products.

The meeting comes after two "legal highs" were found to contain the prescription sedative phenazepam.

Zaid Musa, of Enjoi Products, and Matt Bowden, who imports chemicals used in Kronic, called the meeting after the Herald reported Kronic was being advertised on mainstream radio last week.

Matthew Wielenga from Lightyears Ahead, the company behind Kronic, will also attend.

Mr Musa said the industry was "getting out of control" and the meeting was an effort to rein in behaviour that could lead to an official ban being imposed.

One long-term retailer said sales of synthetic cannabis products "virtually stopped overnight" once the news of phenazepam's presence broke on Thursday.

The meeting will also discuss a code of practice for ingredient testing, limits on advertising, dairies near schools stocking synthetic cannabis and Kronic's pre-rolled joints, which health officials say target younger users.

Screening by Environmental Science and Research (ESR) revealed that Kronic's Pineapple Express and Cosmic Corner's Juicy Puff Super Strength contained phenazepam.

ESR's general manager of forensic research, Dr Keith Bedford, said just over 40 synthetic cannabis products were tested after employers asked about the risks the drugs posed in the workplace.

Although all the analysing had not been completed, Dr Bedford said, "nothing else of the unexpected and alarming nature of finding phenazepam has surfaced".

But he warned consumers not to assume all other products were free of drugs such as the prescription sedative.

"I'm not wanting to imply some kind of blanket assurance that all other products are okay. I simply don't know that."

Dr Bedford said the products contained a "bewildering" number of synthetic cannabinoids in many different combinations. "Products come and go and are reformulated."

Chris Fowlie, co-owner of the Hemp Store in central Auckland, said sales of synthetic cannabis "virtually stopped overnight" after the phenazepam discovery.

He said he had not been not invited to today's meeting, but had a simple message for those who would be attending.

"I'm hoping they pull their heads in, stop chasing the quick buck, and look at the long-term future of the industry."

Mr Fowlie said it was astounding that at a time of intense media interest and clear community concern, some in the industry had paid for radio advertisements.

"It's like some of these guys are just hanging themselves by their own rope. I just can't fathom it."