Ministry of Health public health director Dr Mark Jacobs said the heavy metals in some tattoo inks could be harmful.
A recent Ministry of Health survey revealed most tattoo inks meet its voluntary guidelines for heavy metal but some inks contained more chemicals than recommended.
The risk posed by the heavy metals was unknown but scientists believed the lower the exposure the better, Dr Jacob said.
People considering a tattoo should investigate the ink composition first, he said.
The ministry survey ''Selected samples of tattoo inks for the presence of heavy metals 2013'' was published on the ministry website on Wednesday.
There were 169 inks tested, from 18 different ink brands, and included 118 colours.
The inks tested for arsenic, barium, cadmium, cobalt, chromium (VI), copper soluble, mercury, nickel, lead, selenium, antimony, tin and zinc.
Crazy Horse Tattoo Studio owner Chris Downing, of Dunedin, said he was ''shocked'' by the toxicity levels of some of the ink brands in the survey.
He had never heard of many of the ink brands.
''I don't know where they found them. It must be Chinese stuff.''
He bought organic pigments from Germany, the United States and England and mixed his own ink. He was certain of its safety.
''Basically, I know I can drink mine and I'll be sweet as.''
Although, many of the inks he used were not in the survey, it was good the ministry was being proactive, he said.
''Education is everything,'' Mr Downing said.
