The forestry and transport industries want employers to start testing workers for synthetic cannabis use.
The Institute of Environmental Science and Research has developed tests it says can detect most synthetic cannabis products in circulation in New Zealand.
The tests are for the two most common such substances, JWH-018 and JWH-073, which can be detected in urine up to 72 hours after being used.
The Forest Owners' Association wants employers to use the tests, and is urging schools and universities to follow suit, saying young people who want a job in the industry should clean up first.
The Road Transport Forum says it has zero tolerance for substance abuse and wants synthetic cannabis to be tested for.
The company that imports the chemicals to make synthetic cannabis, Stargate, says employers should focus on whether people are impaired not whether they have recently taken a legal high.