The best mothballs are the ones used correctly: placed inside an airtight container with your clothing, following every instruction on the label. That matters more than the brand, because mothballs are EPA-regulated pesticides, and using them improperly is both illegal and dangerous. The two types available contain either naphthalene or paradichlorobenzene as their active ingredient, and each has distinct tradeoffs in safety, odor persistence, and effectiveness.
Naphthalene vs. Paradichlorobenzene
Every mothball on the market uses one of two chemicals. Both work through sublimation, slowly converting from a solid into a gas that builds up inside a sealed space and kills clothes moths and their larvae. The difference is what happens after.
Naphthalene breaks down quickly once exposed to open air, with a half-life of less than one day. That sounds like an advantage, but inside your body it converts to alpha-naphthol, a compound linked to hemolytic anemia (the abnormal destruction of red blood cells). Kidney and liver damage can also occur with significant exposure.
Paradichlorobenzene lingers much longer in the environment, persisting up to 31 days in air. It distributes into blood, fat, and breast milk in humans. The World Health Organization has classified it as possibly carcinogenic based on mouse studies, though the U.S. EPA considers it “not likely to be carcinogenic to humans.” Paradichlorobenzene mothballs tend to have a slightly less intense odor than naphthalene ones, which is why many people prefer them for home use.
Never mix the two types in the same container. Combining naphthalene and paradichlorobenzene mothballs can cause a chemical reaction that damages your clothing.
How to Use Mothballs Safely
The single most important rule: mothballs must go inside an airtight container. A sealed garment bag, a well-sealed storage bin, or a trunk with a tight-fitting lid all work. The vapors need to build up to a concentration that actually kills moths. In an open closet or a loosely tied garbage bag, the fumes escape into your living space without ever reaching lethal levels for the insects. You get all the health risk and none of the pest control.
Places mothballs should never be used include open closets, attics, crawl spaces, wall voids, vehicles, trash cans, gardens, or anywhere outdoors. Using them outside to repel snakes, rodents, or other wildlife is a common misuse that can contaminate soil, plants, and water. It’s also illegal under federal pesticide law.
One mothball can cause serious harm if eaten by a small child. Children, pets, and wildlife sometimes mistake them for candy or food. If you have young kids or animals in the house, keep sealed mothball containers well out of reach and consider whether a non-toxic alternative might be the smarter choice.
Pheromone Traps for Detection and Control
Pheromone traps are sticky traps baited with a synthetic version of the sex chemicals female clothes moths produce. They lure in male moths, which get stuck and can no longer mate. Traps are available for both common species: the webbing clothes moth and the casemaking clothes moth. Each species requires its own specific pheromone, so a trap designed for pantry moths won’t catch clothes moths.
These traps serve two purposes. First, they tell you whether you actually have a clothes moth problem, which saves you from treating clothing unnecessarily. Second, they reduce the breeding population by removing males. However, pheromone traps alone won’t eliminate an infestation. UC IPM recommends combining trapping with laundering or dry cleaning any garments that have been exposed to moths. Think of traps as a monitoring tool and a supplement, not a standalone solution.
Natural Alternatives and Their Limits
Cedar is the most popular natural moth deterrent, and it does have real chemistry behind it. The oils in cedar wood contain sesquiterpene hydrocarbons, compounds that produce a strong resinous scent. That scent doesn’t directly repel moths so much as it masks the smell of keratin, the protein in wool, silk, and fur that moth larvae feed on. If larvae can’t smell their food source, they’re less likely to settle in.
The catch is that cedar’s effectiveness is temporary. Cedar hangers, blocks, and sachets lose their potency after about three months as the oils evaporate. An antique cedar chest offers far less protection than a new one. You can extend the life of cedar products by lightly sanding the surface to expose fresh wood and reapplying cedar oil, but this requires ongoing maintenance.
Other natural repellents include neem oil (commonly used in moth sprays in the UK), lavender, mint, rosemary, cloves, thyme, and eucalyptus. These can help deter moths from settling in a space, but none will kill an active infestation the way chemical mothballs do inside a sealed container. Natural options work best as prevention: keeping moths from moving in rather than eliminating larvae already feeding on your sweaters.
Getting Rid of Mothball Smell
Mothball odor clings to fabric and embeds itself in wood grain. On clothing, washing or dry cleaning usually handles it. Furniture and wooden storage pieces are harder. The smell can persist for weeks even after the mothballs are removed.
Ventilation is the foundation of any deodorizing effort. Place the item near an open window with a fan blowing air across it and out. Leaving it outdoors in direct sunlight is even better. For wooden furniture, you can use a blow dryer on the surfaces once a day. The heat helps the wood “sweat out” trapped chemicals. Do not scrub wood with water, which drives the odor deeper into the grain.
When the item isn’t actively being aired out, close it up with natural odor absorbers inside: open boxes of baking soda, charcoal briquettes (the regular grilling kind), wadded newspaper sprinkled with essential oils, coffee grounds, lavender sachets, or a bowl of white vinegar. Activated charcoal disks made for pet odor removal also work well. Light sanding on wood surfaces can remove the outermost layer where odor concentrates, but test an inconspicuous area first. Commercial products like deodorizing granules specifically formulated for mothball odor are available if DIY methods aren’t enough.
Choosing the Right Approach
If you’re storing woolens, furs, or silk long-term in a sealed container, paradichlorobenzene mothballs are the more common choice for home use due to their somewhat milder odor and the EPA’s more favorable toxicity classification. But “best” really depends on your situation.
For seasonal closet protection where you’re in and out of your clothes regularly, cedar products combined with pheromone traps give you a non-toxic monitoring and deterrent system. Replace or refresh the cedar every three months. For long-term storage of valuable garments, chemical mothballs in a truly airtight container remain the most effective option, provided you follow the label exactly. For active infestations, start with pheromone traps to confirm the species, launder or dry clean all affected items, and then store cleaned garments with your chosen repellent in sealed containers.
Watch for illegally imported mothballs sold without proper EPA registration. These products may not list their ingredients accurately, and their contents haven’t been evaluated for safety. Stick with products that carry an EPA registration number on the label.