At public gatherings on the first cool nights of winter, the scent of mothballs from stored winter clothing can be suffocating. Woolen clothing is readily consumed by the larvae of clothes moths and it has somehow become common practice to put mothballs in closets to repel moths during the summer.
In fact, neither mothballs (paradichlorobenzene) nor moth flakes (napthalene) repel moths. They are both poisonous to moths, but only if the clothing is stored in a tightly closed bag or box. Closets are not tight enough to build up enough fumes from these two chemicals to kill or repel moths.
More important than the effectiveness of these chemicals on moths is their negative effect on humans. Benzene is a potent human carcinogen. Napthalene can cause damage to lungs and the blood if it is inhaled for long periods. Infants, older persons and persons suffering from asthma are particularly at risk. Perhaps both of these chemicals pose more risks than benefits to our health. Consider their health risks before using moth balls.
Cedar-lined closets are also reputed to repel moths – but their reputation probably derives from well-built cedar chests, which moths could not invade because they were built so tightly. Cedar oil may repel moths at high concentrations but cedar lumber loses most of its oil a few years after cutting. Just because you can smell the cedar in your closet does not mean moths will be repelled by it.
Q: How much cedar wood should I put in my closet to keep moths out of my clothes?
A: If you fill the closet with cedar shavings, the moths will be repelled. They won’t be able to get in! Lots of people believe that cedar chests keep moths out of clothes. In fact, it’s the tightness of the closet or chest that keeps the moths out. Even moth balls and moth crystals are not very effective as moth repellents. They can, however, kill moths if the clothes and chemicals are sealed up tightly in a bag.
The smell of cedar may slightly repel moths – but there are other, better ways to thwart moths. The first thing you should do is to take out all of your clothes and clean them or brush them thoroughly. While the closet is empty, use caulk to seal all of the cracks along the floor.
If you can’t clean all of the clothes, store them in moth proof laundry bags. These can be purchased from your local drycleaner. Each change of seasons, wash or dryclean everything before storing in the bags.