An employee of a major infrastructure and construction company estimates about 40 per cent of the staff in his team has tried synthetic cannabis, primarily to avoid being stung in routine cannabis testing.
Jason*, who works in a team of about 150-170, estimates about 10 to 20 per cent of his team would be regular synthetic cannabis users.
Jason said his employer carried out regular random drug and alcohol tests. To avoid detection in workplace screenings for cannabis, he mainly smokes synthetic cannabis after being told by a person at another company that it doesn't show up in drug tests. That's now changed as the New Zealand Drug Detection Agency can test for synthetic cannabis.
NZDDA Hamilton general manager Steven Trafford said he was getting phone calls every day from businesses wanting to add synthetic cannabis screening to the regime of tests they held.
While NZDDA has been able to test for synthetic cannabis since the strips they use to test passed stringent verifications last year, it was in the past month that Mr Trafford had noticed a marked increase in the number of employers requesting the tests, particularly from sectors such as forestry, construction and engineering.
Mr Trafford said employers were testing for synthetic cannabis "as a matter of course" and in some cases including it in pre-employment screenings. He said business owners were aware of the risks they faced if employees were under the influence of synthetic cannabis and as such they were prepared to incur the additional cost of testing.
Mr Trafford said he could "confidently" say the use of synthetic cannabis was increasing.
"Parallel to that is that more of our clients are mindful of that."
While synthetic cannabis use may be more prevalent among workers in labour-intensive roles, Mr Trafford said it wasn't unreasonable to assume it was also used among white-collar workers.
"Nationally, we know it's not just limited to [workers in] safety-sensitive areas who use cannabis. We've had white collar people fail drug tests."
In Jason's last job, his employer conducted scheduled drug and alcohol tests. He was a cannabis smoker then but he researched a way of continuing to be a "moderate" cannabis smoker and still pass the tests.
Jason says when he first began using K2 it was once a week, then every couple of days, then every day.
"It used to be a nice casual laxy thing but I realised it was becoming a dependency. I realised how much I was relying on it."
Jason's partner was okay with him using K2 at first "because it was a better alternative than getting busted for cannabis".
Jason and his partner became concerned that his behaviour was beginning to change when he smoked K2.
"I felt really funny a couple of times and realised I'd better stop."
He said it was also a "massive strain financially" which added to his decision to try to quit K2.
As well as the drug making him feel tired, Jason said K2 was "horrible" compared to cannabis. But he's not sure legalising cannabis is the solution.
"I'm not 100 per cent sold on legalisation of cannabis but something needs to be done about synthetics. I'd say if you have any mental health issues, don't go there. Just don't touch it full stop."
* Name changed to protect identity.