Are Mothballs Safe for Pets? 

That sharp “mothball smell” is easy to recognize. It can linger in closets, storage boxes, basements, old furniture, and even on clothing long after the mothballs themselves are gone.

For a home shared with cats or dogs, though, the question is not simply whether the smell is unpleasant.

Are mothballs safe for pets—and is the smell itself something pet owners should be concerned about?

The short answer is that mothballs should not be considered pet-friendly household fragrance products. They are pesticides designed to release chemicals into the air, and pets can be exposed through swallowing them, breathing the vapors, or, in some cases, skin contact. Merck Veterinary Manual notes that mothballs may contain naphthalene, paradichlorobenzene, or—in some countries—camphor, and that all of these can cause poisoning in animals. Cats may be particularly sensitive.

That does not mean the faintest trace of an old mothball odor is automatically an emergency. Risk depends on the chemical involved, amount, concentration, duration of exposure, and how the pet came into contact with it.

But it does mean mothballs belong in a very different category from ordinary pet-friendly home fragrance.

First, Mothballs Are Pesticides—not Air Fresheners

The familiar smell of mothballs can make them feel almost like an old-fashioned household deodorizer.

They are not.

Mothballs are pesticide products intended to control fabric-damaging moths. In the United States, common active ingredients include naphthalene and paradichlorobenzene (PDB or 1,4-dichlorobenzene). In some countries, moth-repellent products may also contain camphor.

These solid chemicals slowly turn into vapor.

That vapor is not an accidental side effect—it is part of how the product works. The concentration builds in a closed storage space and kills moths and their larvae.

The National Pesticide Information Center puts it particularly clearly: when you smell paradichlorobenzene mothballs, you are breathing in pesticide vapor.

That distinction matters for pet households.

A mothball is not simply “a strong scent that pets may dislike.” It is a pesticide producing biologically active vapor.

So, Are Mothballs Pet-Friendly?

No. “Pet-friendly” would not be an appropriate description for mothballs.

Merck reports that mothball exposure can affect animals through ingestion, inhalation, and transdermal absorption. Eating a mothball is the most common route, but it is not the only one.

The potential effects also depend on the active ingredient.

Naphthalene exposure can cause gastrointestinal irritation and, with larger exposures, potentially more serious blood-related problems and neurologic signs.

Paradichlorobenzene can cause vomiting, abdominal discomfort, lethargy, tremors and, with sufficiently significant exposure, liver or kidney effects.

Camphor-containing moth products can cause gastrointestinal and neurologic effects and are considered particularly toxic among the common mothball ingredients discussed by Merck.

This is very different from evaluating whether a lightly scented household product is simply too strong for an individual pet.

With mothballs, the chemical is deliberately being released as a pesticide.

Is Mothball Smell Harmful to Dogs and Cats?

The smell deserves more attention than many people give it.

A strong mothball odor means molecules from the product are present in the air. For products containing paradichlorobenzene, NPIC notes that inhalation of vapor is a recognized exposure pathway.

That does not mean that briefly walking past a closet that smells faintly of mothballs is equivalent to eating one.

Exposure is not all-or-nothing.

Think about several variables:

How strong is the odor?
A powerful smell in a small room suggests a different exposure environment than a faint residual odor on an old coat.

How long is the pet in the space?
A cat sleeping in a closed storage room for hours is different from a dog passing through briefly.

Is the area ventilated?
Poor ventilation can allow vapor concentrations to build.

Can the animal physically reach the mothballs?
Ingestion generally represents a much more concerning situation.

What active ingredient is present?
“Naphthalene,” “paradichlorobenzene,” and “camphor” should not be treated as interchangeable.

This is why simply asking “Is the smell toxic?” is less useful than asking what the product contains and how the animal is being exposed.

Why Cats Deserve Extra Caution

Cats spend a lot of time close to household surfaces and frequently groom their coats.

Merck notes that cats are suspected to be more sensitive to mothball exposure than some other species.

That makes several scenarios particularly undesirable in a cat household:

leaving loose mothballs under furniture, placing them in an open closet the cat can enter, scattering them around a basement, or using them in places where residue could come into contact with paws or fur.

Cats also explore tight, enclosed spaces—the exact kinds of storage areas where mothballs are often used.

A product being “out of sight” is not necessarily the same as being inaccessible to a cat.

Dogs Have a Different Problem: Curiosity and Ingestion

Dogs may encounter mothballs differently.

A round mothball on the floor can look like something worth sniffing, licking, or swallowing.

NPIC specifically warns that pets can accidentally eat mothballs, and Merck identifies ingestion as the most common route of mothball poisoning in animals.

This is especially relevant in homes where mothballs are placed:

under furniture, inside open closets, around garages, in attics, near stored bedding, or outdoors in an attempt to repel animals.

A product that is safely contained in accordance with its label is very different from a loose ball sitting where a dog can reach it.

What If a Pet Eats a Mothball?

Treat actual ingestion as a veterinary issue rather than a home-fragrance question.

Possible signs associated with mothball exposure can include vomiting, loss of appetite, abdominal discomfort, lethargy, tremors or other neurologic changes. More serious effects depend on the ingredient and amount involved.

If you know or suspect your cat or dog swallowed a mothball, contact your veterinarian or an animal poison-control service promptly.

Do not assume the product is harmless because the pet seems normal immediately afterward, and do not rely on home remedies.

If possible, keep the original packaging available so the active ingredient can be identified.

One of the Biggest Problems: Using Mothballs in the Wrong Places

People sometimes place mothballs in gardens, garages, crawl spaces or around a property hoping to repel snakes, rodents, cats, raccoons, or other animals.

That can create unnecessary exposure for household pets.

EPA guidance stresses that pesticides must be used according to their labels. The agency has specifically addressed improper mothball use and notes that typical registered mothball products identify specific storage sites rather than unrestricted placement around a home.

NPIC similarly advises against using mothballs as general-purpose animal repellents unless the product label specifically permits that use.

For a pet household, “more mothballs” is not a better solution.

It simply means more pesticide available for a curious animal to encounter.

The Smell of Mothballs Should Not Be Used to Make a Home Smell “Clean”

This is an important distinction for anyone interested in pet-friendly home fragrance.

Mothball odor can sometimes become associated with “stored,” “clean,” or “protected” clothing because generations of people encountered the smell in closets and trunks.

But a strong chemical smell is not the same thing as clean indoor air.

EPA recommends keeping indoor spaces clean, dry, and well ventilated and minimizing exposure to moth repellents.

If the goal is to make a pet household smell fresher, mothballs are solving the wrong problem.

Pet odor management should start with the actual odor source:

washing pet bedding, vacuuming upholstery and carpets, cleaning litter areas, addressing accidents appropriately, emptying trash, and improving ventilation.

Then, if desired, home fragrance can be added thoughtfully.

A pesticide should not be used as ambient fragrance.

What Can Pet Owners Use Instead for Clothing Moths?

If you are using mothballs because you actually have clothes moths, there are nonchemical strategies worth considering before reaching for pesticide products.

The University of California’s Integrated Pest Management program recommends approaches such as laundering or dry cleaning susceptible textiles, vacuuming closets and cracks, proper storage, and using airtight containers. Freezing or heating appropriate items can also be useful in certain circumstances.

That creates a useful pet-home principle:

Control the pest source instead of filling the room with more chemical vapor.

Clean garments before long-term storage.

Vacuum closet edges and hidden areas where larvae may be present.

Store vulnerable wool, fur, feathers and similar materials in tightly sealed containers.

Monitor for actual moth activity rather than treating every closet preventively.

If the infestation is substantial or difficult to control, professional pest-management advice may be more appropriate than improvising with loose mothballs.

“Natural Mothballs” Are Not Automatically Pet-Friendly Either

This is where terminology becomes confusing.

Some products marketed as “natural moth repellents” may contain aromatic herbs, cedar, essential oils, or camphor.

“Natural” does not automatically mean appropriate for cats and dogs.

Merck notes that camphor itself can be an active ingredient in moth-repellent products and can cause significant toxicity in animals.

So replacing a conventional mothball with something labeled “natural camphor ball” does not automatically solve the pet-safety question.

The same rule that applies to home fragrance applies here:

look at the actual ingredient, concentration, product format, and intended use—not the marketing language.

Mothballs vs. Pet-Friendly Home Fragrance

Mothballs also illustrate why the phrase pet-friendly needs context.

A pet-conscious household product is not defined by having a pleasant smell or being made from a familiar ingredient.

Responsible product selection considers:

the formulation, concentration, intended use, route of exposure, room ventilation, product placement, frequency of use, and whether a pet can directly access the product.

Mothballs perform poorly under that framework because their basic purpose involves creating pesticide vapor.

That makes them fundamentally different from a home fragrance product designed to add a controlled ambient scent to a shared living space.

Even then, “pet-friendly home fragrance” should never mean “zero risk in every animal.”

It should mean thinking carefully about how humans and pets share the same environment.

A Better Rule for Homes Shared With Pets

Instead of trying to memorize dozens of “safe” and “unsafe” smells, use a simpler question:

What is this product actually designed to do?

If the answer is:

kill insects through pesticide vapor,

it should not be treated like ordinary home fragrance.

If the answer is:

add scent to a living space,

then you can evaluate fragrance strength, formulation, ventilation, placement, and how your individual pet responds.

That difference sounds obvious, but mothballs sit in a strange cultural category where their smell has become familiar enough that people sometimes forget what the product actually is.

The Bottom Line: Are Mothballs Safe Around Pets?

Mothballs should not be considered pet-friendly.

They are pesticides that may contain naphthalene, paradichlorobenzene, or camphor, and animals can be exposed through ingestion, inhalation, or contact. Ingestion is particularly concerning, while strong or prolonged vapor exposure is also something pet households should avoid.

For cat and dog households, the practical approach is simple:

Keep mothballs inaccessible to pets.
Use them only according to the product label.
Do not scatter them around the home or yard as a general animal repellent.
Do not use mothball odor as a substitute for household odor control.
Consider cleaning, laundering, vacuuming, sealed storage, and other integrated pest-control methods when appropriate.
And if a pet may have swallowed or had significant exposure to a mothball, contact a veterinarian promptly.

A home does not become more pet-friendly by eliminating every scent.

It becomes more pet-friendly by understanding what each household product is actually doing in the shared environment.

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FAQ

Are mothballs toxic to dogs?

Mothballs can poison dogs, particularly if swallowed. The specific effects depend on whether the product contains naphthalene, paradichlorobenzene, camphor, or another active ingredient.

Are mothballs toxic to cats?

Cats can also be affected by mothball exposure, and Merck notes that they may be more sensitive than some other species. Keep mothballs completely inaccessible to cats.

Is the smell of mothballs harmful to pets?

The odor comes from chemicals volatilizing into the air. NPIC notes that when paradichlorobenzene mothballs can be smelled, pesticide vapor is being inhaled. Risk depends on concentration and duration, but strong or prolonged exposure should be avoided.

Can I use mothballs to keep animals out of my yard?

Do not use mothballs as a general animal repellent unless the product label specifically allows that use. EPA and NPIC both emphasize following the pesticide label.

What can I use instead of mothballs for clothing storage?

For clothes moth control, laundering or dry cleaning, thorough vacuuming, monitoring, and storing clean textiles in airtight containers can help reduce reliance on mothballs.

Are camphor mothballs safe for pets?

Do not assume they are. Merck identifies camphor as one of the ingredients used in some moth repellents and notes that it can cause significant neurologic and gastrointestinal toxicity in animals.