Mothballs and solid deodorizer blocks — household safety profile

What is this product?

Conventional mothballs and solid moth-control/storage deodorizer products sold in the United States contain one of three active ingredients: naphthalene, paradichlorobenzene (1,4-dichlorobenzene, 1,4-DCB), or camphor. All three are volatile solid aromatic compounds that sublimate at room temperature, releasing vapors that repel clothes moths (Tineola bisselliella) and carpet beetles from stored textiles. These products are acutely hazardous in ways that are frequently underestimated by consumers, particularly regarding pediatric poisoning risk and specific genetic vulnerability. Naphthalene and 1,4-dichlorobenzene are both classified as IARC Group 2B possible human carcinogens. Naphthalene triggers hemolytic anemia in individuals with glucose-6-phosphate dehydrogenase (G6PD) deficiency — a genetic variant found in approximately 400 million people worldwide, with highest prevalence in African, Mediterranean, and Southeast Asian populations. G6PD deficiency is X-linked, making males disproportionately affected. Naphthalene exposure in G6PD-deficient individuals can cause acute hemolytic crisis with rapid red blood cell destruction, anemia, jaundice, and in severe cases, acute kidney failure from hemoglobin-derived pigments damaging renal tubules. Infants with undiagnosed G6PD deficiency are particularly vulnerable — neonatal hemolytic crisis has been documented from closet naphthalene vapor exposure. Both naphthalene and 1,4-DCB mothballs come in the form of white or cream-colored spheres or cylinders that resemble candy or food items, creating substantial pediatric ingestion risk. Hundreds of cases of childhood mothball ingestion are reported to Poison Control annually. Camphor, the third active ingredient, is rapidly absorbed through the GI tract and skin and causes seizures in infants and young children at doses as low as 1 gram — one or two camphor balls. Paradichlorobenzene (1,4-DCB) is also the active ingredient in widely used toilet bowl deodorizer blocks, creating an additional exposure pathway distinct from the closet/storage mothball context.

What's in it

Click any compound name for its full safety profile, regulatory consensus, and exposure data.

Who's most at risk

• Children — Floor-level exposure, developing respiratory systems

How to use it more safely

• Use in well-ventilated closets or storage spaces away from living areas
• Keep in original packaging or sealed containers
• Place on shelves or hang away from direct contact with clothing and fabrics
• Use only in spaces not accessible to children or pets

Red flags — when to walk away

• Household member with known or suspected G6PD deficiency in family with naphthalene mothball use; African, Mediterranean, or Southeast Asian family ancestry with unscreened infants — G6PD deficiency is common in these populations and substantially increases the risk of hemolytic crisis from naphthalene exposure. G6PD screening at birth (newborn screening) is performed in some US states but not universally. Unscreened infants of unknown G6PD status from high-prevalence ancestry groups face serious risk from naphthalene vapor exposure in enclosed spaces.
• Mothballs stored anywhere accessible to children under 6; mothballs left in open containers or loose in drawers accessible to young children — Mothballs are a documented pediatric ingestion hazard — they resemble candies or mints and have no child-resistant packaging requirement in the US. Even a single naphthalene or 1,4-DCB mothball ingested by a young child causes toxidrome: nausea, vomiting, hemolytic anemia (naphthalene), and CNS effects. Camphor mothball ingestion causes seizures within 1 hour at doses of 1 gram.

Green flags — what to look for

• Cedar wood blocks, chips, or cedar-oil sachets used for moth deterrence; lavender sachets; vacuum-sealed storage bags for long-term textile storage; regular inspection for moths — Cedar and lavender provide effective moth deterrence without IARC Group 2B carcinogens, hemolytic toxicants, or pediatric seizure risk. These alternatives are safe for use in households with children and G6PD-deficient individuals. Airtight storage physically prevents moth access — the most reliable long-term protection.

Safer alternatives

• Cedar chips or blocks — Natural repellent with lower toxicity and pleasant scent
• Lavender sachets or dried herbs — Non-toxic natural deodorizers safe for all spaces
• Activated charcoal odor absorbers — Safer alternative without harmful chemical vapors

Frequently asked questions