All hazards › Household › Mothballs (Naphthalene / Paradichlorobenzene) & cats

Is Mothballs (Naphthalene / Paradichlorobenzene) Safe for Cats?

☠️ Toxic
✅ Cross-checked against veterinary poison-control guidance · Oct 2026 audit
⚠️ Educational info only. If your pet just ate or touched something and looks unwell, skip the reading and call your vet — or Pet Poison Helpline (US): (855) 764-7661, ASPCA Poison Control (US): (888) 426-4435.
No. Mothballs are dangerous to cats, who are especially sensitive to naphthalene — even small amounts can damage red blood cells and the liver.

Why it’s a problem

Cats encounter mothballs by sniffing, licking or stepping on them in closets and storage spaces, then grooming the residue from their paws and fur. Naphthalene damages red blood cells, and cats need a smaller dose than dogs to be affected. Paradichlorobenzene balls are milder but still toxic.

How to keep your pet safe

Keep mothballs in sealed containers stored where cats never go, and wipe up any dust or crumbs near storage areas. Do not scatter them in gardens or attics accessible to roaming cats. Count them so a missing one is noticed quickly.

Warning signs to watch for

Often delayed 24–72 hours: vomiting, drooling, lethargy, weakness, pale or brown gums, rapid or open-mouth breathing, tremors, seizures, jaundice, dark urine.

When to call the vet

Call your vet or a pet poison hotline as soon as exposure is suspected, even without symptoms. Bring the product packaging so the active ingredient is clear. Do not wait for the delayed signs, and do not induce vomiting unless a professional says so.

Common questions

My cat was shut in a closet with mothballs overnight — now what?

Move her to fresh air and call your vet or a pet poison hotline now — fumes and paw residue both count as exposure. Watch for vomiting, drooling or pale gums over the next 72 hours.

How many mothballs can hurt a cat?

Even one naphthalene mothball can seriously harm a cat because they are small and unusually sensitive. Any known or suspected ingestion deserves an immediate call to a professional.

Are cedar blocks a safer closet option?

Yes, cedar products are far safer around cats, though strongly scented essential-oil versions should still be kept out of reach. They repel moths less reliably, so seal stored wool in bags instead.

More household hazards for cats

🐱 Antifreeze (Ethylene Glycol)☠️ ToxicNo. Antifreeze kills cats at tiny doses — just a few licks from a puddle can cause fatal kidney 🐱 Bleach (Sodium Hypochlorite)🚫 Not SafeRisky. Dried surfaces and aired fumes are usually fine, but liquid bleach burns a cat’s mouth an🐱 Rat Poison (Anticoagulant Rodenticide)☠️ ToxicNo. Rat poison can kill cats, though they are more often poisoned by eating affected rodents tha🐱 Snail & Slug Bait (Metaldehyde)☠️ ToxicNo. Metaldehyde is toxic to cats too, though they are exposed less often than dogs — usually by 🐱 Ant Baits & Traps (Borax / Avermectin)🚫 Not SafeNo. Ant baits are low in toxicity for cats, but plastic trap parts and sticky gel residue make t🐱 Permethrin Yard & Bug Sprays☠️ ToxicNo. Permethrin is highly poisonous to cats — even tiny amounts from grooming contaminated fur or

This page is general educational information, not a substitute for professional veterinary advice. Every pet is different — if your animal ate or touched something concerning, contact your veterinarian or a pet poison hotline right away. In the US: Pet Poison Helpline (855) 764-7661, ASPCA Animal Poison Control (888) 426-4435 (fees may apply).