The roots of the kava plant are used to produce a drink which has a sedative effect. It is used throughout the Pacific and is known as 'ava in Samoa and 'awa in Hawaii.
Prime Minister John Key has taken part in 'ava ceremonies in Samoa when he is welcomed to the country.
Otago University toxicologist Dr Leo Schep said the effects of Kava "very quickly" hit the body, and lasted "about two to three hours, maybe a bit longer".
"It's used throughout the world recreationally without any major problems. But the question is, where do you draw the line on recreational use and impinging your job?"
Tongan community leader Melino Maka said it was an integral part of the Tongan community, with great historical significance.
He said if kava was to be tested for in the workplace, there would be a strong response from his community.
The Tongan community partakes in the drink as part of cultural ceremonies including birthdays, funerals and church services.
"It's not an illegal drug, it's part of our culture," Mr Maka said.
Asked whether it could have an impact on one's ability to work, he said: "It's just like anything else -- if you consume too much, it will have an impact."
But he said testing was not fair on those who used it purely for cultural purposes.
An AUT study released last year found that young Tongan men who attended kava clubs were less likely to be involved with drugs, alcohol and gangs.
Mr Maka said he was in Dunedin recently to meet the local Tongan community and promote the Government programmes he is involved with -- and the meeting took the form of a kava ceremony.
"And that's the only way that we can connect with them and have them understand what some of those initiatives are all about," he said.
"It breaks down all the barriers and allows everyone to be on the same level and the information was shared."
Drug Detection Agency chief executive Kirk Hardy said there was currently no reliable method of testing for kava and there was not much of a demand for it to be tested for.
"I think what we've got to look at and take into context is that it's a safety issue that employers have to protect their employees and the general public from, whether it's legal or illegal," he said.
A Goodman Fielder spokesman said the company had not asked the Drug Detection Agency to begin testing its employees in Dunedin for kava use.
"Goodman Fielder is working through a drug and alcohol agreement with its employees," he said.
"The company has a duty of care to ensure its employees are safe in the workplace, which includes ensuring that employees do not have the risk of impairment by any substance (legal or illegal) which could impact on their ability to work safely."
He said First Union members at the Dunedin site had agreed to the company's drug and alcohol agreement.
