What is the damp smell?

It is made up of volatile compounds released into the air by mould and bacteria growing on damp surfaces as part of their metabolism. These are called MVOCs; 1-octen-3-ol, which smells like mushrooms, is one of them.

How do you use Air Biotics for a damp smell?

Spray 3-5 times inside the wardrobe and into the room air, and repeat regularly in enclosed spaces. If damp is the source of the smell, it won't go for good until the damp is dealt with; don't neglect ventilation.

Damp · 4 min read · 3 October 2026

Where does the damp smell come from?

The mould-derived volatile compounds behind the smell of closed wardrobes, basements and bathrooms, and how to tackle damp.

C₈H₁₆O1-octen-3-ol

In short

1The damp smell is made up of volatile compounds released into the air by mould and bacteria growing on damp surfaces.
2These compounds are called MVOCs; their most notable effect is irritation of the eyes and upper airways.
3The smell won't go for good until the source of the damp is dealt with.

If there's a smell, something is growing

As mould and bacteria feed, they release volatile organic compounds as by-products of their metabolism. These are called microbial volatile organic compounds, MVOCs for short. The best known are 1-octen-3-ol, which smells like mushrooms, and geosmin, which gives the smell of wet earth.

A review examined 96 typical MVOCs and the 15 most often measured in damp-damaged buildings. The most notable health effect that emerges is irritation of the eyes and upper airways.

Where does it start?

A damp smell often starts somewhere you can't see: behind a wardrobe against an outside wall, on the bathroom ceiling, in cardboard boxes in the basement, in a pantry with no ventilation.

Damp first, then the smell

The smell is a result of damp. If the damp isn't dealt with, the smell comes back.

01Move wardrobes a few centimetres away from outside walls so air can get behind them.
02Air the bathroom after a shower; if there's an extractor fan, run it for 15-20 minutes.
03Use a dehumidifier in enclosed spaces.
04Apply a probiotic spray inside wardrobes and into the room air, and repeat regularly.

Questions

What is the damp smell?: It is made up of volatile compounds released into the air by mould and bacteria growing on damp surfaces as part of their metabolism. These are called MVOCs; 1-octen-3-ol, which smells like mushrooms, is one of them.
How do you use Air Biotics for a damp smell?: Spray 3-5 times inside the wardrobe and into the room air, and repeat regularly in enclosed spaces. If damp is the source of the smell, it won't go for good until the damp is dealt with; don't neglect ventilation.

Sources

All literature →

01
Microbial volatile organic compounds
Korpi A, Järnberg J, Pasanen AL (2009). Critical Reviews in Toxicology 39(2): 139-193
doi:10.1080/10408440802291497
Finding · ReviewMould and bacteria release volatile organic compounds (MVOCs) as part of their metabolism. The review looks at 96 typical MVOCs and the 15 most often measured in damp-damaged buildings; the most notable effect is irritation of the eyes and upper airways.

These studies were not carried out with Air Biotics. What we say about the product is limited to what is written on its packaging; Air Biotics is not a disinfectant.

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