Are Mothballs Bad For You? | Health Risks Explained

Many of us grew up with the distinct scent of mothballs, a familiar marker of stored blankets or forgotten attics. These small, white spheres have a long history of protecting garments from pests. Understanding what they are made of and how they work helps us grasp their potential impact on our well-being.

What Are Mothballs Made Of?

Mothballs are solid pesticides, designed to slowly release a gas that repels or kills clothes moths and their larvae. The active ingredients are highly volatile organic compounds. Historically, mothballs primarily contained naphthalene, a substance derived from coal tar. Modern formulations frequently use paradichlorobenzene (PDCB) as an alternative.

Naphthalene

Naphthalene is a polycyclic aromatic hydrocarbon. It’s a white, crystalline solid with a strong, distinct odor. When exposed to air, naphthalene undergoes sublimation, transforming directly from a solid to a gas without passing through a liquid phase. This vapor is what acts as the pesticide.

Exposure to naphthalene can occur through inhalation of its vapors, skin contact, or ingestion. It is particularly concerning for young children who might mistake them for candy.

Paradichlorobenzene (PDCB)

Paradichlorobenzene, also known as 1,4-dichlorobenzene, is another volatile organic compound. Like naphthalene, PDCB is a white solid that sublimes at room temperature, releasing a pungent vapor. This chemical is often chosen for its effectiveness against pests and its ability to dissipate over time.

PDCB is also found in some toilet bowl deodorizers and air fresheners, highlighting its use as a deodorizing and pesticidal agent. Its vapors, like naphthalene’s, are the primary route of exposure.

Table 1: Key Active Ingredients in Mothballs

Chemical Name	Primary Pest Use	Core Health Concern
Naphthalene	Clothes moths, carpet beetles	Hemolytic anemia (especially in children), organ damage
Paradichlorobenzene (PDCB)	Clothes moths, mildew, deodorizer	Liver damage, kidney damage, respiratory irritation

How Mothballs Work (and Why That’s a Concern)

The pesticidal action of mothballs relies entirely on the sublimation process. The solid chemicals slowly turn into a gas, filling the enclosed space where they are placed. These vapors are toxic to insects, disrupting their nervous systems and respiratory functions, ultimately killing them or driving them away.

The very mechanism that makes mothballs effective against pests also makes them a concern for human health. The vapors released are not selective; they can be inhaled by anyone in the vicinity. The concentration of these vapors builds up significantly in poorly ventilated or sealed areas, creating a potent exposure risk.

This vapor release is continuous as long as the mothball exists, meaning exposure can be prolonged if not handled correctly. The strong odor serves as a warning, but it indicates the presence of these active chemical vapors in the air.

Health Risks of Mothball Exposure

Exposure to mothball chemicals, even at low levels, can lead to various health issues. The severity of effects depends on the chemical involved, the concentration of vapors, duration of exposure, and individual sensitivity. Children and individuals with certain health conditions are particularly vulnerable.

Acute Exposure Symptoms

Short-term exposure to mothball vapors can cause immediate, noticeable symptoms. These often affect the respiratory and nervous systems.

• Headaches and dizziness are common neurological responses.
• Nausea, vomiting, and abdominal pain indicate gastrointestinal irritation.
• Eye and nasal irritation, along with coughing, point to respiratory tract effects.
• Skin irritation can occur from direct contact with the solid mothball.

Naphthalene exposure carries a specific acute risk: hemolytic anemia. This condition involves the destruction of red blood cells, which can lead to fatigue, weakness, and jaundice. Infants and young children are especially susceptible to naphthalene-induced hemolytic anemia, even from minimal exposure, such as inhaling vapors from clothing stored with mothballs.

Chronic Exposure Concerns

Long-term or repeated exposure to mothball chemicals raises more serious health concerns. These effects can develop over time and impact various organ systems.

• Liver and kidney damage are potential outcomes, as these organs process and filter toxins from the body.
• Respiratory problems, including asthma-like symptoms or chronic bronchitis, can develop from sustained inhalation of irritating vapors.
• Neurological effects, such as tremors or coordination issues, have been reported with prolonged exposure.

Both naphthalene and paradichlorobenzene are classified as possible human carcinogens by various health organizations. The EPA has evaluated these chemicals regarding their carcinogenic potential. Animal studies have shown links to tumor development, prompting caution regarding human exposure.

Table 2: Symptoms of Mothball Exposure

Exposure Type	Common Symptoms	Specific Concerns
Inhalation (Short-term)	Headache, dizziness, nausea, eye/nose irritation	Respiratory distress, vomiting
Inhalation (Long-term)	Liver/kidney damage, chronic respiratory issues	Potential carcinogen, neurological effects
Ingestion (Children/Pets)	Vomiting, diarrhea, abdominal pain, lethargy	Hemolytic anemia (naphthalene), seizures, coma

Who Is Most At Risk?

Certain populations are more vulnerable to the adverse effects of mothball chemicals. Understanding these heightened risks helps in implementing protective measures.

• Infants and Young Children: Their smaller body size and developing organ systems make them highly sensitive. Ingestion of mothballs, which can resemble candy, poses a severe poisoning risk. Inhalation of naphthalene vapors can trigger hemolytic anemia in this age group.
• Pets: Animals, especially dogs and cats, are prone to ingesting mothballs due to curiosity or confusing them with toys. Ingestion can lead to severe poisoning, requiring immediate veterinary attention.
• Individuals with G6PD Deficiency: People with glucose-6-phosphate dehydrogenase (G6PD) deficiency have a genetic condition that makes their red blood cells fragile. Naphthalene exposure can trigger a severe hemolytic crisis in these individuals, leading to life-threatening anemia.
• People with Pre-existing Respiratory Conditions: Individuals with asthma, allergies, or other chronic respiratory illnesses may experience exacerbated symptoms from inhaling mothball vapors. The irritant properties of these chemicals can trigger attacks or worsen lung function.

Safe Use vs. Misuse

Mothballs are pesticides and must be used according to their label instructions. The labels typically specify use in tightly sealed containers, such as garment bags or storage chests. This controlled environment contains the vapors, limiting their spread into living spaces.

Misuse is a widespread problem and a primary driver of health concerns. Scattering mothballs in open closets, attics, gardens, or under houses is dangerous. This practice allows the toxic vapors to disperse freely into the air, leading to widespread exposure for humans and animals.

Using mothballs as general deodorizers or pest repellents for animals like squirrels or snakes is also misuse. These applications are not only ineffective long-term but also contribute to unnecessary exposure to harmful chemicals. The chemicals are designed to sublimate and saturate an enclosed space, not an open area.

Safer Alternatives to Mothballs

Protecting belongings from pests does not require relying on harsh chemicals. Several effective and safer alternatives exist.

• Cedar Products: Cedar wood naturally repels moths and other insects. Cedar blocks, hangers, or chests provide a pleasant scent and a chemical-free deterrent. Re-sanding cedar periodically helps refresh its effectiveness.
• Herbal Sachets: Bags filled with dried herbs like lavender, rosemary, mint, or cloves can deter pests. These natural repellents offer a pleasant aroma and are safe for use around clothing and linens.
• Regular Cleaning and Vacuuming: Consistent cleaning removes moth eggs and larvae before they can cause damage. Vacuuming carpets, rugs, and upholstered furniture regularly helps eliminate potential breeding grounds.
• Airtight Storage Containers: Storing clothing and textiles in sealed plastic bins or vacuum-sealed bags prevents pests from accessing them. This physical barrier is highly effective and eliminates the need for chemical repellents.
• Freezing Items: For smaller items or those suspected of infestation, placing them in a freezer for several days can kill moths, larvae, and eggs. Ensure items are sealed in plastic bags to prevent moisture damage.
• Integrated Pest Management (IPM) Principles: This approach focuses on prevention, monitoring, and non-chemical controls. It involves identifying the pest, understanding its life cycle, and using a combination of methods to manage it. This systematic approach reduces reliance on pesticides. The EPA provides extensive information on IPM strategies.

Proper Disposal of Mothballs

Mothballs are classified as hazardous waste. They should never be thrown in the regular trash or flushed down drains, as this can contaminate soil and water systems. Unused or partially used mothballs require special disposal methods.

Contact your local waste management facility or hazardous waste disposal program for guidance. Many municipalities offer specific collection days or sites for household hazardous waste. Following these guidelines ensures responsible disposal and prevents further environmental or health risks.