Mothball smell does go away, but it can take months or even years depending on how long the mothballs were in place and what materials absorbed the fumes. Left completely untreated in an enclosed space, the odor can persist in wood, fabric, and insulation for years. The good news: with active removal steps, you can cut that timeline down to days or weeks.
Why the Smell Lingers So Long
Mothballs work by slowly turning from a solid into a gas, a process called sublimation. The two chemicals used in mothballs, naphthalene and paradichlorobenzene, both release vapor continuously until the ball is completely gone. That vapor doesn’t just float in the air. It gets absorbed into porous materials like wood grain, upholstery fabric, carpet fibers, drywall, and insulation. Once trapped in these materials, the chemical releases back into the air slowly, which is why a closet or dresser can still smell like mothballs long after the actual mothballs have been removed.
Temperature plays a major role in how fast the smell dissipates. Research on sublimation rates shows that a 10°C (18°F) increase in temperature can quadruple how fast a solid substance releases vapor. Airflow matters even more: increasing air movement across a surface can speed up emission rates by roughly five times. This is why a sealed cedar chest in a cool basement can hold mothball odor for years, while the same chest left open on a warm porch might air out in weeks.
How Long It Takes Without Intervention
On clothing that was stored briefly with mothballs, the smell typically fades within a few days of hanging in fresh air. Heavier items like wool coats and blankets take longer because the fibers trap more vapor. Wood furniture is the worst offender. Mothball odor seeps into the grain of wood and the padding of upholstered pieces, and can last for years without treatment. Entire rooms or houses where mothballs were used heavily, sometimes under floors or in wall cavities to deter pests, can hold the smell indefinitely if those spaces aren’t addressed directly.
Removing the Smell From Clothes
For washable fabrics, run them through a cycle with half a cup of white vinegar instead of detergent. Vinegar breaks down the chemical residue clinging to fibers. If the smell persists after one wash, try again with two tablespoons of baking soda added to the drum. Follow up with a normal detergent wash afterward.
For spot treatment before washing, mix equal parts white vinegar and lemon juice, then dab it onto the areas where the smell is strongest using a clean cloth. The acidity helps neutralize naphthalene residue.
Delicate or dry-clean-only fabrics can’t handle a vinegar wash. For these, steam is the best option. A garment steamer breaks down mothball odor through heat without soaking the fabric. If steaming isn’t available, hang the items outdoors on a warm, breezy day. As a passive backup, placing activated charcoal or bamboo charcoal sachets in the closet or drawer with the garments will slowly absorb the remaining odor over a period of days.
Removing the Smell From Furniture and Rooms
Start with ventilation. Open windows, run fans, and create cross-breezes through the affected space. Given how much airflow accelerates dissipation, this single step makes the biggest difference. On warm days, move furniture outdoors if possible.
For hard surfaces like shelves, floors, and walls, wipe everything down with a solution of equal parts white vinegar and water. This removes the thin film of chemical residue that clings to non-porous surfaces. You may need to repeat this several times for heavily affected areas.
For wood furniture and enclosed spaces like cabinets and drawers, place small bowls of baking soda or bags of activated charcoal inside. Position them in corners, on shelves, and near wherever the smell is strongest. Activated charcoal is particularly effective because its porous structure traps chemical compounds. Replace the charcoal or baking soda every few days until the odor fades. Cedar blocks can also help by introducing a competing scent while the chemical gradually releases.
An air purifier with an activated carbon filter can help clear mothball chemicals from the air in a room. Standard HEPA filters catch particles but won’t do much for chemical vapors. The carbon filter is the key component for this type of odor.
When the Smell Won’t Budge
If you’ve tried ventilation, surface cleaning, and absorbents for several weeks without meaningful improvement, the mothball chemicals have likely penetrated deep into building materials. This is common in older homes where mothballs were placed in attics, crawl spaces, or between walls.
Professional remediation companies sometimes use ozone generators for persistent chemical odors. Ozone reacts with and breaks down many of the same compounds found in mothballs, including polycyclic aromatic hydrocarbons. However, ozone treatment has limitations. Research from Lawrence Berkeley National Laboratory found that while ozone can remove chemicals absorbed into materials, it also causes a burst of airborne contaminants while the generator runs. The space must be completely unoccupied during treatment, and you need to wait several hours after the generator shuts off, with windows open, before re-entering.
For furniture that resists all other methods, sealing the wood with a coat of shellac or polyurethane can trap remaining residue inside the grain and prevent it from off-gassing into the room. This doesn’t remove the chemical, but it effectively blocks the smell from reaching your nose.
The Fastest Approach
A combination strategy works better than any single method. Start by maximizing airflow and warmth to accelerate the natural release of trapped vapor. Clean all hard surfaces with vinegar solution to remove surface residue. Place activated charcoal or baking soda to capture what’s already in the air. Wash or steam fabrics to pull the chemicals out of fibers. For rooms, run an air purifier with a carbon filter to catch ongoing off-gassing. Repeating these steps over the course of a week or two resolves most cases. Deeply saturated wood and building materials are the exception, and those may need professional treatment or sealing to fully resolve.