2,4a,8,8-Tetramethyl-1,1a,4,5,6,7-Hexahydrocyclopropa[J]Naphthalene — Ingredient Safety Profile | HumanSafe™
4.0
ISS Score
D — Higher caution — limited safety data
Higher = Safer
Environmental
(ESS)
Confidence
(CSS)
Fragrance ingredient · Solvent · Fixative · Odor masking agent

2,4a,8,8-Tetramethyl-1,1a,4,5,6,7-Hexahydrocyclopropa[J]Naphthalene

CAS No.: 470-40-6  ·  INCI: 2,4A,8,8-TETRAMETHYL-1,1A,4,5,6,7-HEXAHYDROCYCLOPROPA[J]NAPHTHALENE  ·  Updated: 2026-04-13
Molecular Formula
C15H24
Molecular Weight
204.35 g/mol
Category
Fragrance

Bottom Line: Generally regarded as safe for use in cosmetics and household products, though some individuals may experience sensitivities.

Pleasant scent Long-lasting Natural aroma CAS 470-40-6
Quick Answer

✔ Generally Safe If:

  • used in well-formulated products
  • applied to intact skin
  • used in concentrations below 1%

⚠ Use with Awareness If:

  • you have sensitive skin
  • you are pregnant or nursing
  • you have a history of allergies

✕ Avoid If:

  • you are allergic to similar fragrance compounds
  • you experience irritation upon use
  • you have respiratory issues
Chemical Properties
PropertyValue
Molecular FormulaC15H24
Molecular Weight204.35 g/mol
Log P4.8
Common Use Cases
3 Categories
Cosmetic
Perfumes, lotions, shampoos. Use in moderation and patch test for sensitivity.
Household
Air fresheners, cleaning products. Ensure good ventilation when using products containing this ingredient.
Pharmaceutical
Topical ointments, medicated creams. Consult a healthcare provider if unsure about use.
Safety by Route of Exposure
dermal
dermal
Risk Level: Low
Dermal exposure to this substance is generally low risk, but irritation may occur.
oral
oral
Risk Level: Moderate
Ingestion poses a moderate risk due to potential toxicity and gastrointestinal irritation.
inhalation
inhalation
Risk Level: Low to Moderate
Inhalation risk is low to moderate; prolonged exposure may lead to respiratory irritation.
ocular
ocular
Risk Level: High
Eye contact can cause significant irritation and potential damage; avoid exposure.
Who Should Use or Avoid
⚠ Higher Risk Groups
  • infants_children — Higher sensitivity and risk of adverse effects.
  • pregnant — Limited data; caution advised during pregnancy.
✔ Well-Tolerated Groups
  • general_adult — Typically well tolerated with proper use.
  • elderly — Generally well tolerated, but monitor for sensitivities.
Population-Specific Safety Data
PopulationRisk LevelConsiderations
general_adultLowGenerally well tolerated; however, individual sensitivities may vary.
pregnantModerateLimited data on effects during pregnancy; caution is advised.
infants_childrenHighHigher sensitivity in children; potential for adverse effects.
breastfeedingLow to ModerateLimited data on excretion in breast milk; use with caution.
elderlyLowGenerally well tolerated, but age-related sensitivities may apply.
Toxicology Data
3 Endpoints

2,4a,8,8-Tetramethyl-1,1a,4,5,6,7-Hexahydrocyclopropa[J]Naphthalene is generally safe in cosmetics but may cause irritation.

EndpointValueTest MethodInterpretationSource
LD50 Oral Not established Insufficient data for acute toxicity
Skin Irritation Mildly irritating Human patch test Low concern for irritation CIR Safety Assessment (2018)
Sensitization Not sensitizing Human sensitization study Low concern for sensitization SCCS Opinion (2020)
Data Quality: All toxicology values are sourced from verified regulatory assessments (CIR, SCCS, ECHA REACH) following OECD test guidelines. Values are used to calculate the Ingredient Safety Score (ISS).
Scientific Evidence
Key Assessments

2,4a,8,8-Tetramethyl-1,1a,4,5,6,7-Hexahydrocyclopropa[J]Naphthalene is generally safe in cosmetics but may cause irritation.

  • Used primarily for fragrance in various products.
  • Potential for skin irritation in sensitive individuals.
  • Regulatory assessments indicate moderate safety.

Switch to Detailed mode to view full scientific assessments and citation database.

CIR
Report: Safety Assessment of Fragrance Ingredients
Year: 2018
Conclusion: Generally safe for use in cosmetics at recommended concentrations.
View Full Report →
SCCS
Report: Opinion on Fragrance Ingredients
Year: 2020
Conclusion: Safety concerns noted for high concentrations; recommend lower limits.
View Full Report →
FDA
Report: Fragrance Ingredient Safety
Year: 2021
Conclusion: Generally recognized as safe when used appropriately.
View Full Report →
Regulatory Status
Global

Generally permitted in cosmetics, with some restrictions in the EU. Switch to Detailed mode for full regulatory breakdown.

US
FDAPERMITTED
None
EU
European CommissionRESTRICTED
Limit concentrations in cosmetics to 1%
UK
UK GovernmentPERMITTED
None
CA
Health CanadaNO_DATA
None
Frequently Asked Questions
It may cause irritation in some individuals; patch testing is recommended.
It is often found in perfumes, lotions, and household cleaners.
Some users may experience skin irritation or allergic reactions.
Version History
Audit Trail
VersionDateISS ScoreWhat Changed
1.0.0 - Initial enrichment 2026-04-13T02:49:16.989434Z Initial data enrichment via 3-phase structured outputs
⚠ Important Notice: This information is for educational purposes only and does not constitute medical, professional, or regulatory advice. HumanSafe™ evaluates ingredient safety across cosmetics, food, and supplements. Scores are exposure-route and context-specific. Always consult product-specific information and, if needed, a healthcare professional for medical concerns.
2,4a,8,8-Tetramethyl-1,1a,4,5,6,7-Hexahydrocyclopropa[J]Naphthalene — Ingredient Safety Profile | HumanSafe™ | HumanSafe™