The Ministry of Health says people should not be using mouthwashes that contain alcohol long-term, following a review indicating it can cause cancer.
The review, authored by several independent experts and published in the Australian Dental Journal, says there is sufficient evidence to show that these mouthwashes increase people's risk of developing oral cancer.
The review says ethanol in mouthwash can permeate the lining of the mouth, making it easier for cancer causing substances to cause damage.
Acetaldehyde, a toxic by-product of alcohol that may accumulate in the oral cavity when swished around the mouth, is also believed to be carcinogenic.
One of the authors of the review, Associate Professor Michael McCullough in Queensland, says prolonged use of alcohol-based mouthwashes can increase the risk of oral cancer by four to five times.
He says dentists need to re-think whether it is safe to recommend the use of mouthwashes.
The Health Ministry says more research needs to be done. However, it advises people not to use mouthwashes containing alcohol on a regular, long-term basis without advice from a dentist.
Neil Hewson, from the Australian Dental Association, says most people do not actually need mouthwash if they practise good brushing and flossing.