The Dangerous Myth Of Mothballs

When you think of mothballs do you associate them with pesticides or more of a harmless home remedy that gets rid of just about any unwanted creature you could imagine? I’m thinking most of you feel this pearly white marble or flaked product must be as harmless as dishwashing soap because I see it used in some of the craziest ways. From whole boxes dumped into fireplaces to keep the chimney pest free, to hundreds of little white marbles encircling a house to stop unwanted snakes. What duct tape is to the husband who insists on fixing any household item on his own, mothballs are to that same DIY who has ANY kind of pest control issue.

Mothballs are a pesticide no ifs, ands or buts! Naphthalene is an active ingredient that is commonly used in mothballs and paradichlorobenzene is the other. Both are used in high concentrations in the making of mothball products. Let’s take a minute and see what these chemicals are;

Naphthalene was first registered as a pesticide in 1948. It is a solid that turns into a gas and it indeed kills insects and repels some animals. It is made from coal or crude oil but can also be produced when things burn. Cigarettes, exhaust from cars and forest fires all produce naphthalene. The main routes of exposure to naphthalene are inhalation and skin contact. Once inside your body this chemical breaks down and effects the liver, lungs and kidneys. Common symptoms of exposure are dizziness, headache and nausea. Children that may eat the mothball may have diarrhea, abdominal pain and painful and discolored urination. If someone breathes in enough of the vapor or eats a mothball containing naphthalene, they might develop hemolytic anemia. This is when red blood cells break apart, and no longer carry oxygen the way they should.

Paradichlorobenzene was first registered as a fumigant for moths in 1942. It too, goes from a solid to a vapor and poses many of the same risks as its cousin naphthalene. Irritation of the eyes and nose, nausea, dizziness and vomiting are signs of over exposure but paradichlorobenzene seems less likely to stay in the body as up to 50% can be excreted in one hours time with urination.

So Why Mothballs

Most mothball labels are pretty explicit about not breathing in vapors and avoiding skin contact. They also require that they be used in sealed containers where the gas cannot escape. I’ve not read any directions where it allows for using them in gardens, open areas or attics yet I see this way to often. Whenever you smell the strong odor of mothballs you are breathing in pesticides which in todays society I would think is strictly taboo. The little white marbles are pretty tempting to children as well- they pick them up out of curiosity and even eat them thinking they are some sort of candy.

Still the lure of a wonder product that has the reputation of chasing away pests and is not some sort of toxic spray must be comforting to some people. So many are absolutely convinced that mothballs are the answer to almost every pest control situation and are even less concerned about any hazards. I see it used for mice, squirrels, rats, snakes, roaches, unwanted dogs or cats, flies, fleas, ants and oh yes, even for moths. People with second homes such as snowbirds often sprinkle whole boxes around their home as they lock the door and head north for the summer. I have a few customers whose home wreaks so strongly of mothballs that we wear masks when we go in to perform service while they’re away. I’m guessing that most folks don’t even know that mothballs are pesticides and if they do, they are convinced they are fairly harmless. Besides, the ease of just throwing a 1/2 box out in the garage or up in the attic and letting the smell chase away their troubles is so much more simple than breaking out the spray.

Is there a myth associated with mothballs? Sure there is and I’ll bet you thought I was gonna shoot down everything that they are NOT good for- I might just do that but not today. The myth I’m exposing is one you’ve probably never thought of consciously or passed off with little concern. The myth that mothballs are safe little white marbles and Ok to walk over and around everyday-the myth that mothballs are not pesticides. That is the dangerous myth I want you to be aware of and the one I wish you’d avoid.

About The Bug Doctor

Jerry Schappert is a certified pest control operator and Associate Certified Entomologist with over two and a half decades of experience from birds to termites and everything in between. He started as a route technician and worked his way up to commercial/national accounts representative. Always learning in his craft he is familiar with rural pest services and big city control techniques. Jerry has owned and operated a successful pest control company since 1993 in Ocala,Florida. While his knowledge and practical application has benefitted his community Jerry wanted to impart his wisdom on a broader scale to help many more. was born from that idea in 2007 and has been well received. It is the goal of this site to inform you with his keen insights and safely guide you through your pest control treatment needs.

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  • Postal canary

    Forever. Specially if there is no
    Moving air to help. Heat and air flow is the best thing.
    I get so angry when I hear suggestions of putting mothballs IN OR UNDER SOMEONES HOME!!!!

  • Dave Kelter

    I hung three nylons full of moth balls to get rid of a pesky bird out under our eave. It’s been 3 weeks and no return. Do you think its time to remove them and do you think they will return?

  • Oscar

    I had a problem with cats doing their business in my orchid garden, I put moth balls in the garden, no more cats, rats, or flies in the backyard…

  • Clare Brady

    Very good advice, and I can vouch for both the toxicity of mothballs and getting rid of roaches by cleaning. I once rented an apartment from a slumlord (I didn’t know he was a slumlord at the time); The first night I slept there I saw roaches scurrying next to my bed. Needless to say, I didn’t sleep at all that night! Went out the next day, bought roach hotels and plastic containers for my food. I embarked on a detailed cleaning of the entire apartment (I was a professional cleaner at the time so that helped), kept all food in sealed containers or in fridge, and was diligent about vacuuming every day. I made that apartment so spotless that you could literally eat off the floor. I was successful n eliminating roaches from my apartment, even thought the other tenants in the building still had infestations. So roaches can be eliminated without chemicals, as can almost all pests – just takes a little effort and thought.
    However, my experience with mothballs did not end as well. Years later, I moved into a house that had an odor of mothballs. It seemed to be coming from the hall closet, but I was never able to get rid of the smell even after taking out the floor. Turned out the previous tenant had made a hole in the wall, thrown a box of mothballs inside, and sealed it up. The odor contaminated everything in the house, including my clothes, hair, and skin; I ended up with chemical sensitivity from exposure to the damn stuff. It’s quite simple – mothballs are persistent organic pollutants, and should be banned. They certainly shouldn’t be sold in supermarkets!

  • Clare Brady

    That is terrible – I hope you don’t end up with MCS like I did (see my post above). I swear some folks are addicted to the vile things. I pet-sat for a woman who spread moth flakes all over her carpet and furniture because she thought it helped to dehumidify the house. That house was, and no doubt still is, toxic. The smell is impossible to get rid of.

  • Clare Brady

    No, it will contaminate the hay!

  • Gina1958

    It sounds like you have a huge roach issue. Why not work on getting rid of them permanently? Rid-X plug ins have worked for me, and I use no pesticides in my home.

  • Gina1958

    I have a huge outdoor ant problem. I wanted to take them and spread them around the foundation of the house. I also wanted to put some up in my attic to get rid of spiders. I’ve tried some very intense pest control for the ants and they die off for a while, and within weeks, they’re all back. I am also going to have my trees trimmed away from the roof of my home. Nothing is touching the roof, but I wonder if they can still somehow get there.

  • Joe Desrali

    If you want to boost the octane rating of your gasoline, put a naptha mothball in your tank, when you fill up. Some cars with higher compression, turbocharged, or supercharged engines run better with higher octane gasoline. The mothball quickly dissolves, and you come out much cheaper than purchasing “Premium” gasoline. You need to be sure to use the old fashioned, naptha mothballs. The newer paradichlorobenzine kind won’t work. Besides, they are much more dangerous to use. They just doesn’t smell as bad.
    Jerry is right in what he is saying about mothball pest control use, but they do have their use. You just need to take into account, what Jerry wrote about them and use them accordingly. They can be used in places, that people or pets don’t often venture into, like maybe a storage building, cabin (Just remove them and let the place, air out a bit, when you stay there), seldon used out building on a farm. Even a place where humans or livestock frequent, that’s well ventilated, like some barns, the naptha mothballs should be okay to use.
    Stay away from the paradichlorobenzine mothballs. They could be deadly. …The naptha ones are like being around gasoline too much. Not a good thing but, if you treat them like you would gasoline; you’ll be okay.

  • Javier Villanueva

    I unknowingly threw a whole box of mothballs into an attic. I did this to rid of raccoons. What a mistake that was. 30 minutes later the tenants living there called me complaining about the unbearable smell. So I went back and was only able to find half of the box. What should I do now? It took me 4 hours to find the 1st half. The attic is full of white blown in insulation so you can imagine the camouflage job that’s going on. What should I do?

  • Bill Fish

    You MUST identify the type of ants first. If they are Carpenter Ants, you can ONLINE purchase Advance. I’ve not seen a Carpenter Ant in at least a dozen years since sprinkling some of that stuff out there. They bring it to the nest and it kills the queen.

  • JJ

    How do you use mothballs in your yard to repel snakes and mice?

  • Jennifer Underwood

    I read mothballs will get rid of silverfish. I have regular pest control, but still seem to get silverfish getting into my home (and they are alive and wiggling)…would it be ok to put mothballs outside under the edge of the the exterior walls of the house to keep them away (we have no children)…Do they keep scorpions away?

  • Liz

    Our house is small. About 800 square feet. It’s and old house and we have a mouse problem. I threw about 50 to 60 mothballs under the house to get rid of the mice, but the smell is overwhelming. Is it harmful to us? It’s been 2 days, but I’m afraid it could get worse. Will we be ok?

  • Liz

    Our house is small. About 800 square feet. It’s and old house and we have a mouse problem. I threw about 50 to 60 mothballs under the house to get rid of the mice, but the smell is overwhelming. Is it harmful to us? It’s been 2 days, but I’m afraid it could get worse. Will we be ok or not?

  • Liz

    Our house is small. About 800 square feet. It’s and old house and we have a mouse problem. I threw about 50 to 60 mothballs under the house to get rid of the mice, but the smell is overwhelming. Is it harmful to us? It’s been 2 days, but I’m afraid it could get worse. Will we be ok cause I’m worried.

  • Andrea K.

    It’s Fall, so, I won’t be using my window ACs anymore this year. For the past 3 seasons, I have birds nesting beside & underneath both window ACs. I put up a rubber snake near them…..doesn’t bother them. We went from putting AC covers over the ACs, now, to doubled up tarps & they are constantly tearing into them! Would it be harmful, just, to put a few mothballs under or beside the ACs on the outside window sills, hopefully, to chase these birds away for good. These are tiny Sparrows & Wrens, but are very destructive!

  • They are called mothballs–not bird balls–not snake balls—they are an insecticide.

  • Sharona

    My neighbor (2 apartments down from me) uses these toxic balls of sickness. The smokers won’t even go through my hallway to exit the bldg to smoke their death sticks because of the smell. I’ve had to tape myself into my apartment like a tomb; however, if I didn’t I wouldn’t be able to survive living with these noxious balls.
    I’ve complained several times to the apartment manager (and head of maintenance) about the smell, but because mothballs are considered ‘non-toxic to humans,’ I’m stuck living with the smell.
    Two weeks ago I had brain surgery. I was already moderately malnourished and underweight previous to surgery. Since coming home, I’ve lost 5 lbs because I Can. Not. Eat. Due to the overwhelming nausea caused by the odor which permeated my un-taped apartment while I was in the hospital. Unfortunately, there is no air flow, and I have but one sliding glass door in the apartment and it won’t air out that horrible smell.
    What do I do? I’m at my wit’s end. These mothballs are literally killing me. I live in an Section 8 Apartment Building…do I have any recourse?
    Please, please help me. Thank you.