Naphthalene is a simple organic compound, a bicyclic aromatic hydrocarbon, that is recognizable by its highly distinct and penetrating odor. It is primarily known for its use as a pesticide, particularly in products designed to repel moths and other insects. This white, crystalline substance easily transitions directly from a solid to a gas, a process called sublimation, which is why its scent is so readily detected in the air. Identifying this smell is important because its volatility allows it to spread rapidly through indoor spaces, leading to potential exposure.
The Specific Characteristics of the Naphthalene Scent
The odor of naphthalene is most often described as the quintessential “mothball” smell, a sensory experience that is both strong and intensely pungent. It possesses a sweet, tar-like quality that some may find medicinal or reminiscent of coal. This characteristic scent is due to its high volatility, meaning the compound releases its vapor into the air even at room temperature. The concentration of naphthalene in the air directly correlates with the intensity of the odor perceived. Because it is highly volatile, the smell quickly permeates porous materials like fabric, paper, and wood, making it difficult to eliminate.
Common Household Sources of Naphthalene Odor
The most familiar source of this unique scent in homes is the use of moth repellents, such as mothballs, flakes, or crystals, which are pesticides designed to kill or deter fabric-eating insects. These products are often placed in storage areas, closets, or trunks to protect clothing and blankets. The odor detected is the naphthalene gas slowly being released from the solid form into the air. While moth repellents are the primary consumer source, the compound is a polycyclic aromatic hydrocarbon (PAH) also found naturally in fossil fuels like coal and crude oil, and it is a component of coal tar. Lesser sources in a home environment can include tobacco smoke, vehicle emissions, and certain wood preservatives or older toilet bowl deodorizers.
Health Considerations Regarding Naphthalene Exposure
Exposure to naphthalene vapors poses health concerns, making odor recognition a significant first step toward mitigation. Acute exposure can cause irritation of the eyes, nose, and throat, often accompanied by headaches, nausea, and vomiting. Chronic exposure is more serious, as naphthalene is broken down into metabolites that damage red blood cells, potentially leading to hemolytic anemia. This risk is particularly elevated for infants, young children, and individuals with glucose-6-phosphate dehydrogenase (G6PD) deficiency. The U.S. Environmental Protection Agency (EPA) has categorized naphthalene as a possible human carcinogen, emphasizing the importance of reducing long-term exposure.
Removing Naphthalene Odors from the Home
The first step in eliminating the odor is to locate and safely dispose of the source material, such as mothballs or flakes, ensuring the container is sealed. Once the source is removed, aggressive ventilation is necessary to dissipate lingering vapors by opening windows and using fans. Since the chemical readily adheres to porous surfaces, affected items like clothing, linens, and upholstery must be cleaned. Washable fabrics should be laundered, often requiring the addition of baking soda or white vinegar to the wash cycle; non-washable items benefit from airing outdoors in sunlight. To address persistent odors in enclosed spaces, absorbent materials like baking soda or activated charcoal can be placed in the affected areas, and hard surfaces should be wiped down with a mild soap or vinegar solution.