Gardai have admitted that using mouthwash does cause some drivers to fail roadside breath tests.
However, they have reassured clean-teethed motorists that it only happens in a small number of cases.
The Roads Policing Bureau says a more in-depth test carried out in a Garda station will clarify if a driver is over the limit.
Superintendent Eddie Golden said there is no need for drivers to stop using mouthwash.
However, he did suggest concerned drivers could switch to a "mouthwash that has no alcohol in it whatsoever".
Mouthwash is not a major issue for members of the Garda Traffic Corp.
The big problem, according to Superintendent Golden, is "people that are driving with excess alcohol in their systems".
