The dangers of moth balls and their safer alternatives

There are a lot of smells that bring me back to childhood, and mothballs are one of them.  Living in a northern state before the era of synthetic fleece meant bundling up in wool.  I knew there were two enemies to our wool sweaters that might ruin them: accidentally washing and shrinking them, and moths.  I never saw that many moths flying around, but maybe that’s because my mother used moth balls in the winter clothing storage bins, and the faint smell of moth balls on your wool sweaters was just a price of keeping them from season to season, and staying warm.

Moth balls are made of naphthalene or paradichlorobenzene, both of which are toxic to humans.  These chemicals are manufactured in a solid form, but evaporate over time into gas, which is how we’re most likely exposed to them.  Naphthalene is the traditional “mothball” smell.  In humans, naphthalene is broken down to alpha-naphthol, which is linked to the development of hemolytic anemia. Kidney and liver damage may also occur. Alpha-naphthol and other metabolites are excreted in urine. The International Agency for Research on Cancer (IARC) of the World Health Organization (WHO) concluded that naphthalene is possibly carcinogenic to humans. The U.S. EPA classified naphthalene as a possible human carcinogen, also based on animal studies. (Naphthalene Fact Sheet)  Paradichlorobenzene is also a colorless to white solid crystal which evaporates, with a strong pungent odor.  It can induce respiratory irritation in low concentrations, and fatigue, headache, nausea, vomiting, and weight loss in higher concentrations.  It’s also highly suspected to be a carcinogen in rat studies, inducing liver tumors, and may disrupt the endocrine system.  

Besides killing moths, paradichlorobenzene damages some plastics.  One safety label for paradichlorobenzene mothballs specifies that “Do not use in containers, dry cleaning and garbage bags, or closets that allow vapors to escape into occupied rooms.”  Whew!  If something damages plastic, you definitely don’t want to bring it into your home, especially if children are present and can mistake the white crystal balls for candy in an unsupervised moment.

Well, since many people still enjoy wearing wool, and moths still like to munch on it, what are some alternatives to mothballs to keep the dang moths away?  This article highlights that preparation for storage is just as important, because moth eggs and larvae can hide in unwashed clothing, and moths are also attracted to certain scents, like soap, perfume, food, and sweat.  So wash and completely dry your items carefully, and then store them.  Next, here are some ways to store them moth-free:

• Cedar is an age-old moth-deterrent, and still a great natural choice.  its unique aromatic oils, including the organic compounds cedrol, thujopsene and cadinine, actively disrupt moth behavior. The scent of cedar, which is pleasant for most people, is highly effective at deterring moths by affecting their neurological systems, making it difficult for them to lay eggs or remain near the wood. (The Science Behind Cedar Wood: How It Repels Moths Naturally) If you don’t have a cedar-lined wardrobe or trunk, you can get cedar accessories in all shapes and sizes to add to your closet and/or drawers: planks, balls, chips contained in sachets, etc… Cedar’s natural oils act as a powerful deterrent to moths and other insects—without the need for harmful chemicals. For centuries, cedar has been used for its insect-repelling properties and cedarwood oil remains a trusted ingredient in natural insect repellents.  Studies, including one published by ResearchGate, confirm that cedar is effective in repelling clothes moths, flour beetles, cockroaches and ants.  (The best natural alternatives to mothballs for moths)  It’s good to replace the cedar every few years when you notice the wood drying out and becoming scent-less (for this reason, old cedar wardrobes and trunks are fairly useless in their moth-repellent quality, so adding cedar to them is recommended as well).

• If you don’t like the smell of cedar, lavender has also been found to repel moths with good success, due to its terpenes 1,8-cineole and camphor.  (Why Can Lavender Be Used to Repel Moths? – The Chemistry of Lavender)  You can buy lavender sachets online and give them a gentle squeeze (to release more of their essential oil) as you notice the lavender scent waning, then replace as necessary.  You can also make your own sachets using a high-quality, natural lavender essential oil. 

• Here’s one that always works providing you use it properly: airtight storage.  If the wool clothing is sealed in a plastic bin, no moths can get in (provided you don’t leave the top open too long).  In fact, doubling up on protection by using cedar or lavender AND airtight storage is a great idea for valuable, hard to replace items. 

• Pheromone moth-prevention traps are recommended by a pest-control company who has been working with the company for some time.  They work by providing a stronger attractant than your wool clothes, for three months (make sure to replace them on time). 

In addition to NOT using traditional mothballs, we would not recommend the following: 

• Bounce Dryer Sheets: although they do seem to repel pests (including rodents), they are not rated well on the Environmental Working Group’s (EWG) website because of the chemicals used in them, so we would not recommend placing them in with your clothing. 

• Moth repellent sprays like cedar sprays because not all ingredients may be disclosed.

• “Moth-killing” products like this one containing transfluthrin are deemed to be safe by the EPA, but at least one rodent study concluded it can interfere with fertility and pregnancy outcomes.

Photo by Habranthus on Unsplash