Mothball Breath: Causes and Solutions

Mothball breath is so-called because one’s breath can smell overpoweringly like mothballs. This musty, benzene-like odour can be unpleasant both for you and your network of friends and family.

Interestingly, mothball breath may arise slowly over a period of weeks or months, or may suddenly appear within the space of days. In more severe cases the smell of mothballs can be quite severe, requiring rapid treatment to avoid unnecessary embarrassment.

Oddly, while many instances of bad breath have quite obvious cures, mothball breath is rather different to most cases of halitosis and may stem from a wide range of potential causes. Therefore, it is important to address the potential causes in order, so as to eliminate one potential impact after another.

Causes of Mothball Breath

There is no single cause of mothball breath; instead it may be caused by a range of different issues. While some of these may be oral in origin, a number of different medical conditions and dietary impacts may also lead to the musty smell of mothballs on the breath.

In contrast to popular opinion, there appears to be no evidence that lactose intolerance can lead to breath that smells like mothballs.

Here are some of the most common causes:

Poor Oral Hygiene

Mothball breath may be caused by bacteria in the mouth. These sulphur-producing bacteria thrive on food particles and sloughed mouth cells. As they digest these food items they produce volatile sulphur compounds (VSCs) which can smell like mothballs.

One of the most common sources of halitosis is therefore a lack of oral hygiene – or associated dental problems such as tooth decay or calculus.

Under such conditions the bacteria are able to rapidly replicate, and in doing so the volume of VSCs produced increases. This can cause the breath to smell like mothballs.


Sinus problems have long been linked to the issue of bad breath – especially in the case of mothball breath.

An infection of the sinuses results in the production of excess proteins, which the body struggles to break down, yet act as an ideal food source for bacteria. The secretions themselves may also have an unpleasant odour to them.

These two elements mean that VSCs can be breathed out in considerable volumes, making for malodorous breath.


“Keto breath” is a well-known phenomenon among those partaking in a low-carb diet. In place of burning carbohydrates for food the body burns stored fat – and in doing so releases chemicals called “ketones”.

While ketones tend to smell quite rich and fruity (akin to nail polish), some dieters have found that their breath comes to resemble the smell of mothballs.

Kidney Conditions

Less commonly, some kidney conditions are known to cause halitosis. Heavy drinkers, in particular, may be impacted by this potential cause.

Acid Reflux

While acid reflux (GERD) most commonly makes its presence felt in the form of a sour or bitter taste in the mouth (thanks to the improper placement of stomach acids) there is some evidence to suggest that GERD may also be a causal factor in mothball breath.

Certain Foods

Lastly a range of spicy or pungent foods may also be to blame for halitosis.

Elements such as onions and garlic, or spicy foods like curry, can all have a significant impact on the breath.

How to Get Rid of Mothball Breath

As you can see, based on the wide range of potential causes of mothball breath it also follows that getting rid if it isn’t always easy. That’s not to say it’s impossible; just that you’ll need to be methodical about ticking off one potential cause after another.

Here are some of the most effective solutions we’ve come across:

Implement an Effective Oral Hygiene Routine

Let’s start off with the basics; to rule out the most common cause it is wise to start with a thorough and highly-effective routine of cleaning and sterilising your mouth.

Start off by brushing and flossing twice a day, for at least two minutes at a time.

Add to this daily scraping of your tongue, where many sulphur-producing bacteria are to be found.

Lastly be sure to use an effective anti-bacterial mouth rinse which will fight the bacterial load in your mouth. This is in contrast to standard deodorising mouth rinses which simply mask the smell; instead treat the root cause with a product such as UltraDEX Daily Oral Rinse.

Visit Your Dentist

Just because you’re not experiencing any discomfort doesn’t necessarily mean that there aren’t any issues in your mouth. If you suffer from mothball breath it is a wise idea to consult your local dentist for a check-up.

Your dentist will be able to check for any issues – such as minor tooth decay or tartar – and propose effective solutions.

Visit Your Doctor

Due to the fact that many potential causes of mothball breath are health-related – such as sinus infections or kidney problems – it also pays to visit your General Practitioner. Explain the issue you’ve been experiencing, and ask them to check for any obvious causes.

On many occasions, for example, individuals struggling with significant halitosis find that they’re suffering from sinusitis. After a short course of medication, they’re soon back to their former fresh-breathed self.

Consider Your Diet

Have you changed your diet recently? For example, have you switched to a calorie-reduced diet or have you begun to enjoy more spicy foods as of late? If so, consider eliminating these factors one-by-one to see if your mothball breath goes away in time.

Drink More Fluids

The sulphur-producing bacteria which give off unpleasant odours are naturally kept under control by your saliva. The pH of this helps to fight the build-up, and so keep your breath fresh during the day.

However, if your salivary rate drops, so does the body’s ability to control oral bacteria. This is one of the most common causes of so-called “morning breath”, as the flow of saliva drops while we’re asleep at night.

One of the best ways to counteract a lack of saliva is to sip gently on plain water.

So keep a bottle with you at all times and aim to keep yourself properly hydrated throughout the day. Avoiding alcohol and cigarettes can also help to keep the mouth properly lubricated.

Chew Sugar-Free Gum or Mints

One final trick, which not only improves salivary flow but also provides a pleasant masking effect, is to consider the use of gum or mint. Alternatively consider the use of a breath spray or mouthrinse sachet which can be discretely kept in a pocket or bag.

Note, however, that masking your mothball breath should only be considered a short-term solution; we would advise you to seek the appropriate medical advice to help deal with the root cause of the problem.