The purpose of mothballs is controlling clothes-eating moths, but some people use them to control other pests, including rodents, snakes and other insects. One end result is a lingering odor that's as bad for you as it smells. There's no magic bullet for neutralizing mothball odor -- the best strategy is to turn up the heat, provide plenty of ventilation and wait. Consider using natural moth-control alternatives in the future.
The traditional ingredient in mothballs is naphthalene, a compound that can cause serious health problems, especially for children. More recent mothball formulations replace naphthalene with paradichlorobenzene, a slightly less toxic compound, but one that can still cause dizziness and nausea. Both chemicals, which are possible carcinogens, enter the air through sublimation -- mothballs change from a solid to a vapor state without becoming a liquid. If you can smell the characteristic odor of mothballs, it means that solid pieces are in the vicinity, although they might be too small to see. You need to eliminate these pieces to be rid of the odor.
Clean the Floor and Walls
When a room has a persistent mothball odor, the first step to eliminating it is to thoroughly clean the area to get rid of any solid particles -- wear gloves and a respirator while doing this. Vacuum the floor and empty the bag outside. Then wash the walls and woodwork with a mild detergent solution. If the residue is minor, a thorough cleaning may take care of the problem, but if the odor lingers, it's often because small particles have lodged in the pores of unfinished wood, in furniture fabrics, carpets and clothing. Clothing can be laundered, but removing particles from upholstery and carpeting isn't as easy.
Heat and Ventilation
The best way to deal with the odor coming from furniture is to provide heat to increase the rate of sublimation and also provide plenty of ventilation. If you can, move affected furniture outside and leave it in a sunny place for several days. Furniture that's too large to take outside should at least be moved close to a window with a strategically placed fan blowing the VOCs outside. If it's impractical to raise the temperature in the room or use a space heater, you'll have to wait longer for the solids to sublimate and the smell to dissipate.
Deep Cleaning and Alternatives
Mothballs in drawers or closets can crumble, leaving small particles in the pores of the wood, and if assiduous cleaning doesn't remove all of these, you may have to seal the wood with varnish or paint to get rid of the odor. Running an ozone generator may help, but keep in mind that ozone is a pollutant and can create another, more serious, odor problem. To avoid mothball odors in the future, consider using alternatives, including cedar shavings, eucalyptus leaves, peppercorns, lavender or rosemary. Store any of these in a cheesecloth bag out of direct contact with your clothes.