“I use a lot of perfume as I get into and out of the car. Can perfumes and aftershaves cause a positive breathalyser? If I was pulled over for an RBT, should I notify the officer about my perfume?
As with other products that contain alcohol, such as mouthwash, hand sanitizer and even certain foods, perfumes and aftershaves can potentially cause a positive reading when you are pulled over for a random breath test (RBT). If you recently applied a fragrance, or have been spraying the product in the car, the alcohol vapors in the air around you could be detected by the breathalyser, leading to a positive reading.
In Australia two different devices are used by police. In most states and territories, a ‘blowing device’ is used to establish a driver’s blood alcohol concentration (BAC). In NSW and ACT, however, ‘speaking devices’ are also used and the alcohol contained in fragrances is more likely to be detected by these as they may pick up the ‘ambient air’ in the car.
Perfumes are basically composed of two main liquids – perfume concentrate and ethyl alcohol. The concentrate is a mixture of natural and chemical substances that make the fragrance unique. This can’t be applied to the skin in this form and must be diluted and that’s where alcohol comes in, being present from 60% up to 95% by volume in some products.
Although most of these products contain alcohol, it’s important to note that some use water or vegetable oil to dilute the concentrate. Those will not cause an issue when it comes to RBT.
The alcohol content in aftershave is typically a little lower but can vary depending on the product, ranging from around 50% to 70% by volume. Some of the older, more traditional aftershaves contain higher concentrations of alcohol to act as an astringent, i.e., tightening the skin after shaving and closing up any nicks or cuts. Some police who’ve conducted RBTs believe that aftershaves and colognes are more likely to be detected by breathalysers than perfumes, simply because some young men tend to overuse the products, creating more ‘ambient air’.
Wearing perfumes, aftershaves or any other fragrances that contain alcohol should never cause a full licence holder to fail a breathalyser. Young drivers, however, who must have a 0.00 BAC could potentially have an issue. It very much depends on how much of the product you use, when you used it and where you applied it. Young drivers should never keep or use these products in their car – spraying them onto themselves or simply using it in an attempt to make their car smell better is not a good idea. If someone gets into your car and smells strongly of fragrance, or you overdid it a little when you applied it onto yourself, the best way to ensure that you don’t get a positive breathalyser should you get pulled over and tested is to simply open the windows for a while.
Should you inform the officer that you’ve used perfume? Realistically, if you’ve used enough to cause a positive test you probably won’t need to – they’re likely to smell it themselves! Most police are well aware that fragrances can cause this issue and if the smell is that obvious they’ll take that into account and if you fail, you’ll likely be given the opportunity to take a second test.
First published: January 2025
