What Causes a House to Smell Like Mothballs?

The smell of mothballs is known to keep moths from invading homes and consuming stored items such as clothing and bedding. Mothballs have also been rumored to keep snakes, mice and other pests away. Mothballs are a form of chemical pesticide that leave behind a heavy and unmistakable smell, often long after the mothballs themselves are gone.

In many cases, if it smells like a mothball, it is a mothball. If you are not the first person to live in the house, there is a good chance that mothballs were used in the home by the previous owner and the smell remains. In some cases, mothballs may be wedged in difficult-to-locate places in hopes of preventing pests from entering the residence, and you will have to search the home thoroughly to remove any mothballs that you may have missed in your initial cleaning.

Mothballs are made of naphthalene, a chemical that evaporates quickly and leaves a strong odor behind. If used for long periods or in poorly-ventilated spaces, the odor of dissipated naphthalene can remain long after the mothballs have been removed. In this case, you may need to air out the house for several days and place products known to eliminate smells, such as baking soda or activated charcoal.

Naphthalene is present in more than just mothballs, though that is where it is most commonly found, and what its smell is most easily identified with. Tobacco smoke can also contain naphthalene and leave behind an odor similar to mothballs, depending on the type of tobacco product that was smoked. Areas with high pollution tend to have a high concentration of naphthalene in the air. Companies that produce ink, dye, coal, tar, preserve wood or tan leathers also use naphthalene to the point where the smell may be noticeable. If you live near a source of naphthalene, your house may take on a strong mothball type smell.

Cleaning your house thoroughly can help get rid of lingering mothball or naphthalene odors. In some cases, you may need to remove the insulation because it has absorbed the smell and will cause the odor to linger for a long time. If you live in an area with a significant naphthalene odor, you may want to purchase air fresheners as well as an air purifier to help cut down on the smells.