Are Mothballs Dangerous To Breathe? | Health Insights

Many of us grew up with the distinct scent of mothballs, often associated with stored clothing or attics. While they seem like a harmless household item, the chemicals that give them their characteristic odor are potent pesticides designed to deter pests, not to be inhaled by humans or pets.

What Exactly Are Mothballs?

Mothballs are solid pesticide products designed to protect clothing and other materials from fabric pests like moths and carpet beetles. They work by slowly releasing a vapor that is toxic to these insects.

The two primary active ingredients found in mothballs are naphthalene and paradichlorobenzene (PDB). Historically, naphthalene was more common, but PDB has become prevalent in many modern formulations.

• Naphthalene: This chemical is a polycyclic aromatic hydrocarbon. It sublimes readily, meaning it transitions directly from a solid to a gas at room temperature, releasing a strong, distinct odor.
• Paradichlorobenzene (PDB): PDB is an organic compound that also sublimes, releasing vapors that are toxic to insects. Its odor is often described as less pungent than naphthalene.

It is crucial to understand that mothballs are regulated pesticides. Their use is strictly controlled by labels, which specify where and how they can be safely deployed. Misusing them, such as placing them in open areas or inside homes as air fresheners, directly contradicts their intended purpose and poses health risks.

The Core Danger: Chemical Vapor Inhalation

The very mechanism that makes mothballs effective against pests also makes them hazardous to breathe. As naphthalene or paradichlorobenzene sublimes, it releases a continuous stream of chemical vapors into the surrounding air.

When these vapors are inhaled, they enter the lungs and are absorbed into the bloodstream. From there, the chemicals can circulate throughout the body, affecting various organs and systems. The concentration of these vapors increases in enclosed or poorly ventilated spaces, escalating the risk of exposure.

Many people mistakenly believe that the smell of mothballs simply indicates their presence, without recognizing the odor signifies active chemical release. This odor is a direct indicator of chemical exposure. The longer one breathes these vapors, the greater the potential for adverse health effects.

The U.S. Environmental Protection Agency (EPA) registers mothballs as pesticides. This designation means they are intended to kill living organisms and must be handled with extreme caution. Using them in ways not specified on the label, particularly in residential areas where people or pets are present, is unsafe and illegal.

Naphthalene vs. Paradichlorobenzene: Key Differences in Health Impact

While both naphthalene and paradichlorobenzene are toxic, their specific health effects can differ. Understanding these distinctions helps clarify the risks associated with each type of mothball.

Naphthalene Exposure Risks

Naphthalene is a strong irritant and a known hemolytic agent. This means it can damage red blood cells, leading to a condition called hemolytic anemia. This is particularly dangerous for certain vulnerable populations.

• Hemolytic Anemia: Naphthalene exposure can cause red blood cells to break down, reducing the blood’s ability to carry oxygen. Symptoms include fatigue, weakness, pale skin, and shortness of breath.
• Liver and Kidney Damage: Prolonged or high-level exposure can strain and damage these vital organs, which are responsible for filtering toxins from the body.
• Cataracts: Some studies link chronic naphthalene exposure to the development of cataracts in the eyes.
• Carcinogenicity: The International Agency for Research on Cancer (IARC) classifies naphthalene as “possibly carcinogenic to humans” (Group 2B), based on evidence from animal studies.

Paradichlorobenzene (PDB) Exposure Risks

PDB also poses significant health concerns, particularly regarding organ damage and potential carcinogenicity.

• Liver and Kidney Damage: Similar to naphthalene, PDB can cause damage to the liver and kidneys, affecting their function.
• Neurological Effects: Exposure can lead to symptoms like dizziness, headaches, and tremors.
• Respiratory Irritation: Inhaling PDB vapors can irritate the nose, throat, and lungs, causing coughing and breathing difficulties.
• Carcinogenicity: The IARC classifies PDB as “possibly carcinogenic to humans” (Group 2B), also based on evidence from animal studies.

Table 1: Key Differences Between Naphthalene and Paradichlorobenzene Exposure

Feature	Naphthalene	Paradichlorobenzene (PDB)
Primary Health Concern	Hemolytic Anemia, Liver Damage	Liver & Kidney Damage, Neurological Effects
IARC Classification	Possibly Carcinogenic (Group 2B)	Possibly Carcinogenic (Group 2B)
Odor Strength	Strong, distinct “mothball” smell	Less pungent, but still noticeable

Immediate Health Effects of Exposure

Even short-term exposure to mothball vapors can trigger a range of symptoms. These immediate effects are typically due to the irritant nature of the chemicals and their initial impact on the body.

Symptoms can vary in severity depending on the concentration of the vapors, the duration of exposure, and individual sensitivity. Children and individuals with pre-existing conditions often experience more pronounced effects.

• Respiratory Irritation: Coughing, sore throat, burning sensation in the nose and throat, and difficulty breathing.
• Eye Irritation: Redness, watering, itching, and a burning sensation in the eyes.
• Headaches and Dizziness: These are common neurological symptoms of chemical exposure.
• Nausea and Vomiting: The chemicals can upset the digestive system, leading to feelings of sickness.
• Fatigue and Weakness: General malaise and a lack of energy can occur.

If you experience any of these symptoms after being exposed to mothball odors, it is important to move to fresh air immediately. Persistent or severe symptoms warrant prompt medical attention. The Centers for Disease Control and Prevention (CDC) provides detailed information on chemical exposures and their health impacts.

Long-Term Risks and Chronic Exposure

The dangers of mothballs extend beyond immediate discomfort. Chronic or repeated exposure to low levels of mothball vapors can lead to more serious, long-lasting health problems. These effects often develop gradually and may not be immediately apparent.

Continuous inhalation means the body is constantly processing these toxic chemicals, which can overwhelm the body’s detoxification systems over time. This sustained chemical burden can contribute to significant organ damage and other severe conditions.

1. Organ Damage: Prolonged exposure to both naphthalene and paradichlorobenzene can cause cumulative damage to the liver and kidneys. These organs are crucial for detoxifying the body, and their impairment can lead to serious health complications.
2. Neurological Issues: Chronic exposure can contribute to persistent headaches, dizziness, confusion, and other neurological disturbances. Some individuals may experience memory problems or difficulty concentrating.
3. Respiratory Illnesses: Long-term irritation of the respiratory tract can exacerbate existing conditions like asthma or lead to chronic bronchitis. The constant inflammation can damage lung tissue over time.
4. Blood Disorders: For naphthalene, the risk of hemolytic anemia increases with chronic exposure, particularly in susceptible individuals. This can lead to persistent fatigue and other symptoms related to reduced oxygen transport.
5. Cancer Risk: As mentioned, both naphthalene and paradichlorobenzene are classified as “possibly carcinogenic to humans.” This means that while direct human evidence is limited, animal studies suggest a potential link to cancer development with prolonged exposure.

These long-term risks highlight why mothballs should never be used in ways that allow their vapors to accumulate in living spaces. The subtle, persistent smell indicates ongoing chemical exposure.

Table 2: Summary of Health Effects by Exposure Type

Exposure Type	Common Immediate Effects	Potential Long-Term Effects
Acute (Short-term)	Headaches, Nausea, Eye/Throat Irritation	None typically, if exposure is brief and mild
Chronic (Long-term)	Persistent Headaches, Fatigue, Respiratory Issues	Liver/Kidney Damage, Hemolytic Anemia (Naphthalene), Cancer Risk

Who Is Most Vulnerable?

While mothball vapors are harmful to everyone, certain individuals and groups are particularly susceptible to their toxic effects. Their unique physiological characteristics or behaviors increase their risk.

• Infants and Young Children: Children have smaller body masses, meaning a lower dose of chemicals can have a more significant impact. They also breathe more rapidly, increasing their inhalation rate. Furthermore, their developing organ systems are more vulnerable to damage. Toddlers often explore their surroundings by putting objects in their mouths, increasing the risk of direct ingestion.
• Individuals with G6PD Deficiency: People with glucose-6-phosphate dehydrogenase (G6PD) deficiency are at a significantly higher risk of developing severe hemolytic anemia from naphthalene exposure. This genetic condition makes their red blood cells fragile and prone to breakdown when exposed to certain chemicals.
• Pets, Especially Cats: Animals, particularly cats, are highly sensitive to mothball chemicals. Cats lack the specific enzymes needed to properly metabolize naphthalene, making them very susceptible to poisoning. Symptoms in pets can include vomiting, diarrhea, lethargy, tremors, and liver damage.
• Individuals with Pre-existing Conditions: People with respiratory conditions like asthma or chronic obstructive pulmonary disease (COPD) may experience aggravated symptoms from inhaling irritant vapors. Those with existing liver or kidney issues are also at higher risk for further organ damage.

Understanding these vulnerabilities underscores the importance of strict adherence to safety guidelines and avoiding mothball use in areas accessible to these sensitive populations.

Safe Handling and Alternatives

Given the dangers of breathing mothball vapors, proper handling and consideration of alternatives are paramount. The goal is to eliminate exposure while still protecting belongings from pests.

Safe Handling Practices

If you must use mothballs, always prioritize safety and follow label instructions precisely:

1. Read the Label: Use mothballs only as directed on the product label. Never use them in quantities greater than recommended or for purposes other than pest control.
2. Airtight Storage: Place mothballs and treated items in sealed, airtight containers or bags. This prevents vapors from escaping into living spaces. Do not use them in open closets, attics, or basements where vapors can freely circulate.
3. Ventilation: When opening containers with mothballs or retrieving treated items, do so in a well-ventilated outdoor area. Allow items to air out completely before bringing them indoors or wearing them.
4. Keep Away from Children and Pets: Store mothballs in locked cabinets or areas inaccessible to children and pets to prevent accidental ingestion or prolonged inhalation.
5. Proper Disposal: Dispose of unused mothballs and treated items according to local hazardous waste guidelines. Do not flush them down drains or throw them in regular trash, as they can contaminate water and soil.

Effective and Safer Alternatives

Many effective pest control methods do not involve hazardous chemicals, offering safer ways to protect belongings:

• Airtight Storage Containers: The simplest and most effective method is to store clothing and linens in sealed plastic bins, garment bags, or vacuum-sealed bags. This physically prevents pests from accessing items.
• Cedar Products: Cedarwood naturally repels some insects. Cedar chests, hangers, or sachets can offer a pleasant-smelling, non-toxic deterrent. Note that cedar’s effectiveness diminishes over time, and it needs to be refreshed (e.g., by sanding).
• Lavender Sachets: Dried lavender is another natural repellent that many people find pleasant. Place sachets in drawers or closets with stored items.
• Regular Cleaning and Inspection: Frequent vacuuming, dusting, and washing of stored items can prevent pest infestations. Inspect items before storing them and periodically during storage.
• Temperature Control: Storing items in cool, dry conditions can deter pests. Extreme heat or cold treatments (e.g., freezing items for a few days) can also kill existing pests.

Choosing these safer alternatives significantly reduces the risk of chemical exposure for everyone in your home.