An antibacterial product found in Colgate Total toothpaste should not be sold over the counter in New Zealand, says an environmental chemist.
Canterbury University senior lecturer Sally Gaw says she does not use triclosan, which is found in Colgate Total toothpaste, baby wipes, soaps, sports clothes and toys.
She said the chemical potentially had important uses but should not be used in homes, as a study had shown the benefits are no better than washing your hands with soap and water.
Gaw said triclosan should not be sold over the counter in New Zealand.
However, despite concerns over the use of a antibacterial product found in Colgate Total toothpaste, its manufacturer is adamant it's safe to use.
Colgate-Palmolive has responded in a statement to concerns raised in a recent article around the presence of triclosan in its range of toothpaste - a substance some argued should be used sparingly or not at all.
The agent has been linked to negative effects on the environment and a range of potential health issues.
But a Colgate spokesperson said users could be "fully confident in the safety of our toothpaste for daily use".
"It continues to be approved as safe and effective through a rigorous review by the US Food and Drug Administration and is approved by regulatory authorities in Europe, Australia, Canada, and New Zealand.
"Colgate Total is clinically proven to work better than other toothpastes to reduce harmful plaque germs and prevent gingivitis, providing an important health benefit in New Zealand, where one third of adults suffer from gum disease."
On Thursday an article was published which called for the product not to be sold over the counter.
Meanwhile, Popular scientist Michelle Dickinson, who goes under the guise of Nanogirl, has also tweeted on the issue.
Dickinson told the Herald her tweet was to show the science is still inconclusive and the sweeping headlines designed to scare the public about a product they use was not backed up with evidence.
She said there was no scientific evidence that triclosan in soap was more effective at preventing the spread of germs as plain soap and water, but there is disease prevention benefit from using triclosan in toothpaste.
She said some of the research papers on the US Food and Drug Administration website showed the science only seems to have been tested on rats and mice.
"The studies that show negative effects have been very short term experiments using high doses of triclosan.
"I don't believe enough research has been carried out yet to make wide sweeping statements about dangers to human health," Dickinson said.
She said the doses used in toothpaste are very low compared with the rat studies and also shown to prevent gingivitis (a form of gum disease).
Enthusiastic toothbrushers are being warned to stay away from Colgate Total toothpaste, or at least to use it sparingly.
The toothpaste is one of the few toiletries in New Zealand that still uses triclosan, an antibacterial commonly found in soaps, toothpastes and body washes until September last year, when the US Food and Drug Administration banned it from soap because of possible health risks.
Triclosan has been linked to changes in hormone function, liver and kidney damage, and is a suspected carcinogen.
Consumer NZ researcher Jessica Wilson said the FDA ruling had seen it quickly disappear from many toiletry products, but not all.
"The publicity on triclosan has prompted manufacturers to start removing it from their products, so we have seen it disappearing from handwashes.
"However, it's still used in everything from hand soaps to toothpaste, and it's permitted in our cosmetics at a concentration of 0.3 per cent."
One of the most commonly available products containing it is Colgate Total toothpaste.
Triclosan can be useful for fighting diseases such as gingivitis, but Wilson said it wasn't needed for everyday use.
"Our main concern is that it's being used in products where it doesn't need to be used.
"Triclosan is a very broad-spectrum product and given its environmental effects and potential health effects, regulators really need to be taking a precautionary approach.
"There are no good reasons to be using this every day, avoid, unless you've been advised by a medical practitioner that this is the best option."
Last year, the Environmental Protection Authority received an application to check if triclosan's use in New Zealand products should be reassessed.
The EPA said it had found grounds for changing New Zealand's approach to the "hazardous substance" of triclosan, but that nothing had happened since then.
The EPA said there would need to be another request for changes to be made, and whoever made the request would need to partially fund the research to guide those changes.
Foodstuffs, which owns the Pak 'n Save and New World supermarket chains, said after the FDA ruling last year it contacted suppliers, and asked whether they were using triclosan in their antibacterial products.
"Suppliers either advised that their products did not contain triclosan or any of the other ingredients listed by the FDA or if it was present, products were being reformulated by October 2017.
"The only exception is Colgate Total, which has recognised benefits around the treatment of gingivitis.
"Our private-label products including Pams and Value do not contain any of the ingredients listed by the FDA."
Countdown spokeswoman Kate Porter said they decided to remove triclosan from Countdown's own brand products some time ago, and only a few products are still being reformulated.
"We're also having conversations with retail suppliers in New Zealand about what their position is on triclosan, and any plans they have to address concerns regarding their products."
Last month, an international group of 200 scientists and medical professionals called for further restriction of the use of the chemical.
The call was backed by New Zealand scientists including Cawthron environmental toxicologist Dr Louis Tremblay.
Studies on lab animals have shown a link between triclosan and hormone disruption, leading to problems including infertility, impaired brain development, and impaired heart function.
The FDA has also noted a link to the overuse of triclosan, and the rise of antibiotic-resistant bacteria.