Ingredient
1-Naphthol
1-Naphthol is flagged for pregnancy, breastfeeding, postpartum, trying to conceive, PCOS and general use. The concern behind the strongest flag is absorbed into the body and fetal development.
- Alpha-naphthol
- 1-Hydroxynaphthalene
- α-Naphthol
Verdict by profile
Truva checks every ingredient against six profiles. Jump to any of them for the full assessment.
- Strongest verdict
- Not Recommended
- Its verdict for pregnancy, the profile this one is worst in
- Profiles flagged
- 6 of 6
- Counting avoid, high risk and medium risk
- Irritancy
- 4 of 5
- Higher means more likely to sting or redden
1-Naphthol and pregnancy
Not Recommended
- Absorbed into the body
- Fetal development
- Known teratogen
1-Naphthol is a synthetic aromatic compound historically used in hair dyes and industrial chemical processes. It is not commonly found in modern pregnancy-safe cosmetics due to significant safety concerns. According to ECHA and toxicology studies, 1-naphthol can be absorbed through the skin and has demonstrated toxic effects in animal studies. The compound has potential mutagenic properties and may interfere with fetal development. Naphthalene derivatives have been associated with blood disorders and liver toxicity, and their effects on pregnancy outcomes have not been adequately studied to establish safety. Medical professionals universally recommend avoiding this ingredient during pregnancy. The EU has heavily restricted 1-naphthol in cosmetics, and it is prohibited in leave-on products. ACOG and most healthcare providers advise pregnant women to avoid products containing this ingredient entirely. There is no safe level of exposure established for pregnancy.
1-Naphthol and breastfeeding
Not Recommended
- Passes into breast milk
- Infant exposure
- Absorbed into the body
1-Naphthol is a toxic aromatic compound that can be absorbed through skin contact. Its chemical structure and properties suggest potential for systemic distribution and accumulation. While specific studies on breast milk transfer are limited, the compound's known toxicity profile, potential for systemic absorption, and possible effects on blood cells make it unsuitable for use during breastfeeding. Naphthalene compounds have been documented to cause hemolytic anemia and other blood disorders. The AAD and lactation consultants recommend that breastfeeding women avoid exposure to potentially toxic aromatic compounds. Given the serious health risks associated with 1-naphthol and the availability of safer alternatives, this ingredient should be completely avoided during breastfeeding. If accidental exposure occurs, contact a healthcare provider immediately.
1-Naphthol and postpartum
Not Recommended
- Irritant
- Common allergen
- Carcinogen concern
1-Naphthol poses significant health risks regardless of pregnancy or breastfeeding status. The compound is a known irritant and allergen that can cause skin reactions, and it has concerning toxicity data. For postpartum women not breastfeeding, the same general safety concerns apply. The ingredient's potential carcinogenicity, mutagenicity, and systemic toxicity make it unsuitable for cosmetic use. Postpartum recovery is a time when the body may be more vulnerable to environmental stressors, making avoidance of toxic compounds particularly important.
1-Naphthol and trying to conceive
Not Recommended
- Fertility effects
- Absorbed into the body
- Builds up in tissue
Women trying to conceive should avoid 1-naphthol due to its potential mutagenic properties and systemic toxicity. The preconception period is critical for minimizing exposure to potentially harmful substances. While specific fertility data is limited, the compound's known toxic effects on cells and potential for accumulation make it unsuitable during the preconception period. Healthcare providers recommend establishing a clean beauty routine free of toxic chemicals when planning pregnancy.
1-Naphthol and PCOS
Not Recommended
- Irritant
- Interferes with hormones
1-Naphthol is a toxic aromatic compound with no legitimate benefits for skin care or PCOS management. Its potential health risks far outweigh any theoretical cosmetic uses. While specific data on 1-naphthol's effects on hormonal conditions is limited, the compound's toxicity profile and potential for systemic effects make it inappropriate for use by anyone, including women with PCOS. Aromatic compounds with known toxicity can potentially interfere with various metabolic and hormonal pathways. Women with PCOS should avoid 1-naphthol entirely and choose cosmetic products with safer, well-studied ingredients. There are numerous effective and safe alternatives for any cosmetic purpose this ingredient might theoretically serve.
1-Naphthol and general use
Not Recommended
- Irritant
- Common allergen
- Carcinogen concern
1-Naphthol is a synthetic aromatic compound with significant safety concerns that make it unsuitable for cosmetic use by the general public. It is a known skin and respiratory irritant. According to ECHA and various toxicology databases, 1-naphthol poses risks of allergic skin reactions, eye damage, and potential long-term health effects including carcinogenicity concerns. The compound can be absorbed through the skin and may cause systemic toxicity. Repeated exposure may lead to sensitization and more severe allergic reactions over time. The EU has heavily restricted this ingredient in cosmetics, and it is banned in many leave-on products. Consumers should avoid products containing 1-naphthol and choose formulations with safer, modern ingredients. If exposure occurs, wash skin thoroughly and seek medical attention if irritation develops.
Everything else flagged for the same profiles
Related ingredients
Ingredients suggested in place of 1-Naphthol, each one with its own page here.
Ingredients that raise the same concerns.
Where this came from
Truva summarises published guidance from bodies including ACOG, the FDA, the EU SCCS and the Cosmetic Ingredient Review. It has no access to your medical history and it is not a substitute for your doctor, dermatologist or midwife. These assessments have not been reviewed by a clinician, and nothing here is a diagnosis or a prescription. If you are pregnant, breastfeeding or being treated for PCOS, take the ingredient list to the person looking after you.
Assessment last pulled from the ingredient database on .
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