The label is the law. Read your product's label before you mix or apply; the rates here come from the labels listed under Sources.
- Active ingredient
- Naphthalene (CAS 91-20-3)
- Chemical class
- A polycyclic aromatic hydrocarbon: a white crystalline solid with a characteristic odor, made from crude oil or coal tar, that turns into a gas.[3][2]
- Mode of action
- Vapor that kills moths in a sealed space; NPIC says how naphthalene kills moths is not understood[2][1]
- Signal word
- Enoz Old Fashioned Moth Balls: Warning[1]
Not a squirrel, bat or snake repellent
When EPA reviewed naphthalene in 2008, registered products included indoor repellents for bats, tree squirrels and birds in attics and wall voids, and outdoor repellents for snakes, rabbits, rats and mice.[3]
The current Enoz moth ball label, revised in 2026 under EPA's registration review, says the product is not for controlling squirrels, bats and birds inside the home, and its directions cover only clothes moths in airtight spaces. The label also states that using this product in a manner inconsistent with its labeling violates federal law.[1]
Health effects to know about
Infants have developed anemia from clothing, diapers or blankets that were stored with mothballs and not washed afterward, and babies born to women who ate mothballs or breathed the vapor during pregnancy have had hemolytic anemia.[2]
Animal studies suggest naphthalene can cause cancer: the International Agency for Research on Cancer calls it possibly carcinogenic to humans, and EPA classified it as a possible human carcinogen.[2]
Naphthalene was first registered as a pesticide in the United States in 1948. In the environment most of it turns into a gas, with a half-life ranging from under a day in air to over 80 days in soil.[2]
Where it is used
Use moth balls only in clean, airtight containers and closets. The label's test is simple: if you can still smell the product after sealing the container, it isn't airtight enough.[1]
The label limits it to cloth containing wool or wool blends and says not to mix naphthalene or use it with other moth-control chemicals.[1]
Dry clean, wash or brush items before storing them, and keep them sealed with the moth balls for at least 7 days; the odor fades when they're aired out.[1]
NPIC puts it plainly: when you smell mothballs, you are inhaling the pesticide.[2]
Products and registrations
| Product | Registrant | EPA Reg. No. | Active % | Formulation | Signal word |
|---|---|---|---|---|---|
| Enoz Old Fashioned Moth Balls[1] | Willert Home Products, Inc. | 1475-74 | 99.95% | solid moth balls (wrapped packets, loose balls or pre-filled stations) | Warning |
Label rates
| Product | Use | Pests | Rate |
|---|---|---|---|
| Enoz Old Fashioned Moth Balls | Clean, airtight chests, trunks, garment bags and storage closets | Clothes moths, their eggs and larvae, on wool and wool blends | 4 oz product per 12.4 cu ft of airtight space[1] Larger packages scale the same way: 1 lb treats up to 50 cubic feet and 3 lb up to 150. Each pre-filled station treats up to 3 cubic feet. Keep the space sealed at least 7 days. |
How to apply it, step by step
1. Protective gear
- This is a WARNING-signal product: it may be fatal if inhaled, so don't breathe the dust or vapors. It is also harmful if swallowed or absorbed through skin and moderately irritating to the eyes.[1]
- Keep it off your skin, eyes and clothing, and don't open the sachets or take the stations apart. Wash with soap and water after handling and before eating, drinking, chewing gum or using tobacco, and wash contaminated clothing before wearing it again.[1]
2. Before you spray
- Use it only to kill clothes moths and their eggs and larvae on cloth containing wool or wool blends, inside clean, airtight chests, trunks, garment bags or storage closets.[1]
- Never use dry cleaning bags, garbage bags or any container that lets vapor escape into rooms where people live. If you can still smell it after sealing the container, the container isn't airtight and can't be used.[1]
- Keep it where children and pets can't get to it. It isn't for controlling squirrels, bats or birds inside the home, and it isn't for sale in California.[1]
- Dry clean, wash or brush the items first, and don't mix moth balls with other moth-control chemicals.[1]
3. Mixing
- There's nothing to mix; you match the amount to the space. Height times width times depth gives cubic feet, so a trunk 4 ft long, 2 ft wide and 3 ft high holds 24. The label puts an average garment bag at 12 cubic feet, a large trunk at 24, a reach-in closet at 64 and a walk-in closet at 200.[1]
4. Applying
- Use only the amount for the space: 4 oz treats up to 12.4 cubic feet, 8 oz up to 24.8, 1 lb up to 50 and 3 lb up to 150, and each pre-filled station up to 3 cubic feet. Bigger spaces may take more packages, but never put in more than the label specifies for the area.[1]
- Activate a station by pulling its two halves apart until they click, then set it in the container or hang or stand it with the wires provided. Close the container or closet tightly.[1]
5. After you spray
- Keep the space sealed for at least 7 days. The odor fades once treated items are aired out.[1]
- Moths are active all year, so replace moth balls as they dissipate to keep stored clothes protected.[1]
First aid
- If inhaled, move the person to fresh air; if they aren't breathing, call 911 or an ambulance and give artificial respiration, then call a poison control center or doctor.[1]
- If swallowed, call a poison control center or doctor immediately, don't induce vomiting unless told to, and don't give the person any liquid, or anything by mouth if unconscious. On skin, remove contaminated clothing and rinse for 15 to 20 minutes; in the eyes, rinse gently for 15 to 20 minutes, taking out contacts after 5. NPIC, 1-800-858-7378, also gives emergency treatment information.[1]
Storage, spills and disposal
- Store it in the original container in a dry place that children and pets can't reach. It is combustible, so keep it away from heat and open flame.[1]
- Put an empty package in the trash or recycling; for a partly used one, call your local solid waste agency, and never put moth balls down an indoor or outdoor drain.[1]
From the safety data sheet
- Willert's safety data sheet for the 99.95% naphthalene moth balls uses the GHS signal word Danger, while the EPA label uses WARNING. It classifies the product as harmful if swallowed, able to cause genetic defects and cancer (both Category 1B), possibly fatal if swallowed and it enters the airways, and a flammable solid.[4]
- The sheet also classes naphthalene as very toxic to aquatic life with long-lasting effects, says prolonged or repeated contact may dry and irritate the skin, and warns that drinking alcohol may make its toxic effects worse.[4]
- It notes that the National Toxicology Program lists naphthalene as reasonably anticipated to be a human carcinogen. Among chronic effects it lists possible harm to the bone marrow and blood-forming system and to the liver; symptoms of exposure include difficulty breathing, coughing or wheezing, and dizziness.[4]
- For protection the sheet lists tightly fitting safety goggles, impervious gloves, long-sleeved clothing and a chemical-resistant apron, and says not to breathe the vapors. It says no respiratory protection is needed under normal use conditions.[4]
- Keep the moth balls away from heat, sparks and flames, in tightly closed, properly labeled containers in a cool, well-ventilated place, and store them locked up. The sheet says the product shouldn't be released into the environment and should be disposed of according to local regulations.[4]
Safety and environmental hazards
People
Signal word WARNING: the label says it may be fatal if inhaled, and it is harmful if swallowed or absorbed through skin. NPIC reports headaches, nausea, dizziness and vomiting from the vapors, and breathing enough vapor or eating a mothball can cause hemolytic anemia, in which red blood cells break apart. People with an inherited enzyme deficiency are at much greater risk.[1][2]
Pets
Small children and pets may eat mothballs because they look like candy or treats. Dogs that eat naphthalene mothballs may show lethargy, vomiting, diarrhea, loss of appetite and tremors, and the label says never to place it where children or pets can reach it.[2][1]
Bees and pollinators
EPA's 2008 reregistration review had no honey bee toxicity data and could not quantify bee risk, but given how naphthalene is applied it did not expect effects on insects. The moth ball label carries no bee statement and keeps use inside sealed containers and closets.[3][1]
Fish and water
NPIC rates naphthalene moderately toxic to several fish species, water fleas and Pacific oysters and slightly toxic to green algae. EPA's 2008 review did not expect acute risk to freshwater animals from the registered uses. Never put unused moth balls down any drain.[2][3][1]
Common questions
- Do mothballs keep snakes or squirrels away?
- Moth balls aren't labeled for that. This label's directions cover only clothes moths in airtight containers, it says the product is not for controlling squirrels, bats and birds inside the home, and it states that using the product in a manner inconsistent with its labeling violates federal law.[1]
- How many mothballs do I need for a closet?
- Package sizes scale with the space: 4 oz treats up to 12.4 cubic feet and 1 lb up to 50. The label puts a reach-in closet at about 64 cubic feet and a walk-in at about 200, and the closet has to be airtight.[1]
- Is the mothball smell harmful?
- The smell is the pesticide vapor. NPIC says vapors have caused headaches, nausea, dizziness and vomiting, and the label warns that it may be fatal if inhaled and allows it only in sealed, airtight containers and closets.[2][1]
- What should I do if a child swallows a mothball?
- Call a poison control center or doctor immediately. The label says not to induce vomiting unless told to and not to give the person any liquid. NPIC notes that small children are at greatest risk because mothballs can look like candy.[1][2]
Sources
- U.S. EPA Pesticide Product Label System, “Enoz Old Fashioned Moth Balls master label label, EPA Reg. No. 1475-74 (EPA-stamped, Mar. 16, 2026).” www3.epa.gov/pesticides/chem_search/ppls/001475-00074-20260316.pdf (accessed 2026-11-08)
- National Pesticide Information Center, “Naphthalene General Fact Sheet (reviewed December 2010).” npic.orst.edu/factsheets/naphgen.html (accessed 2026-11-08)
- U.S. Environmental Protection Agency, “Reregistration Eligibility Decision for Naphthalene, EPA 738-R-07-010 (September 12, 2008).” archive.epa.gov/pesticides/reregistration/web/pdf/naphthalene-red.pdf (accessed 2026-11-08)
- Willert Home Products, Inc. (copy hosted by whatsinproducts.com), “Enoz Old Fashioned Moth Balls Safety Data Sheet (Willert Home Products, Inc., issued March 1, 2016, revised March 8, 2022; EPA Reg. No. 1475-74).” whatsinproducts.com/app/webroot/files/brands_pdf/1705157702.pdf (accessed 2026-11-08)