How does your apartment smell

When a smell in your home is a mystery

Theresia A. has not felt at home in her living room for a few months now: Sometimes when she's sitting in front of the television in the evening, an acrid smell suddenly hits her nose. Then her eyes water, her nose runs. "It smells pungent, kind of poisonous," she says. She can't explain where the stench is coming from.

There are experts for this, such as the olfactory expert Peter Tappler. He is often confronted with such supposedly inexplicable smells in living rooms and tries to get as much information as possible during his first phone call. You can get a taste of it on site. "But when inspecting the site there is often no smell," says Tappler about the classic demonstration effect. However, some odors can be measured and quantified with devices. For this purpose, a device is set up in the room through which the room air is drawn.

People's sensitivity to bad smells has increased in recent years, says Tappler. "Bad smells in the living room used to be completely normal," said Tappler. That has changed with the increasing need for hygiene.

Mold and the smell of tar

In general, smells are subject to fashion: The smell of new furniture was associated with progress in the 1950s, explains Tappler. Today this smell is no longer accepted. A particularly common cause of musty smells is mold or metabolic products (MVOCs) that are released into the room by the mold.

The smell of tar that penetrates the walls from the building fabric can also make the air thick. Wet PVC flooring, on the other hand, can smell like cowshed, which many do not know. Often it is also solvents that cause the stink in an apartment. "And rotten smells are always an issue," says Tappler. Often a dead mouse or pigeon is lying somewhere. If it is damp, the sweet smell of decay will soon spread around the house. A common cause of bad air is also sewer odor - for example when a siphon has dried out and there is no longer an odor barrier to the sewer system.

Few of these smells are poisonous. What they have in common, however, is that they can be extremely psychologically stressful for the residents. And even physically: Anyone who smells atypical smells can react to them with symptoms such as burning eyes and runny nose. Symptoms similar to those that occur when inhaling pollutants - even if the smell does not come from a toxin at all. This phenomenon is called toxic copy. "So it is difficult to separate which odors are harmful to health and which are not," says odor expert Tappler, who incidentally only attests to a mediocre sense of smell.

Diagnosis: total loss

Sometimes experts can only diagnose a total loss of the house in the face of unbearable odors. In prefabricated houses from the 1970s, for example, there is always a musty, musty smell that can be traced back to chlorine anisoles that arise in the wooden frame construction. Although it is toxicologically harmless, it even sticks to the clothing of residents. In such cases, renovating the house does not always pay off. The same applies if the acrid fuel oil smell is due to the fact that fuel oil has diffused into the wall.

Tappler clarifies that not all puzzles can be solved by an odor expert. Once a colleague was called to a mission because there was a strong smell of horseradish in a company room. The reason for this has not yet been found.

Theresia A. hopes, however, that her olfactory riddle can be solved in the living room. Perhaps, she now thinks, it is the old television - and is going to buy a new one soon. (Franziska Zoidl, February 25, 2018)