Mothball Poisoning: Risks, Symptoms, and Safe Handling

Mothballs are classified as pesticides and are designed to slowly release toxic vapours that repel insects. Some types contain naphthalene, a chemical that can be harmful if swallowed, inhaled, or handled improperly. Even products marketed for household use can pose serious health risks—especially to children and pets.

This article is intended for public education and prevention. It does not replace medical advice or emergency care. If exposure or ingestion is suspected, seek help immediately.

Why Mothballs Can Be Dangerous

When swallowed, naphthalene can damage red blood cells, interfere with oxygen delivery throughout the body, and lead to complications involving the kidneys, brain, and heart. Inhaling mothball fumes over time can also cause poisoning and irritation.

Some mothballs contain paradichlorobenzene, which is generally less toxic than naphthalene but can still cause health effects with improper use or prolonged exposure.

Signs and Symptoms of Mothball Exposure

Health effects depend on the type of mothball, the amount of exposure, and how it entered the body.

Possible symptoms include:

• Abdominal or stomach pain

• Nausea and vomiting

• Headache or dizziness

• Fatigue or weakness

• Irritation of the eyes, nose, or throat

• Seizures or loss of consciousness in severe cases

• Reduced oxygen delivery to vital organs

Symptoms may develop gradually, especially with ongoing inhalation of fumes in enclosed spaces.

Inhalation Risks from Mothball Fumes

Mothballs work by releasing vapours that kill or repel insects. Breathing in these fumes for extended periods—particularly indoors—can irritate the lungs and contribute to poisoning.

Long-term inhalation exposure may occur when mothballs are:

• Used in poorly ventilated spaces

• Left loose in closets, storage areas, or living spaces

• Misused to repel animals in attics, garages, or outdoors

How to Safely Handle and Store Mothballs

Safe handling greatly reduces the risk of accidental exposure.

Important safety tips include:

• Store mothballs and packaging out of reach of children and pets

• Follow all label instructions carefully

• Use mothballs only as directed, and never loose in living spaces, attics, eaves, or outdoors

• Wash or air out clothing and bedding thoroughly before use

• Dispose of mothballs as hazardous waste, according to local guidelines

Mothballs are meant for sealed storage containers, not open areas.

What to Do if Exposure Is Suspected

If someone may have swallowed mothballs or is reacting to fumes:

• Contact Canada Poison Centres immediately at 1-844-POISON-X

• Do not induce vomiting unless directed by professionals

• Remove the person from the source of exposure if safe to do so

• Follow all instructions provided by emergency or poison specialists

Early guidance can help prevent serious complications.

Understanding Naphthalene

Naphthalene is produced from coal tar or crude oil and is also released during combustion. It can be found in:

• Mothballs and pest repellents

• Vehicle exhaust

• Cigarette smoke

• Smoke from forest fires

When inhaled, the body breaks naphthalene down into chemicals that can damage cells and tissues. While its exact insect-repelling mechanism is not fully understood, the strong odour and toxicity are key to its effects.

Educational Note

This article is provided for general learning and safety awareness only. It is not intended to diagnose or treat poisoning. Any suspected exposure to mothballs or their fumes requires prompt professional guidance.