Ingredient review

Hexahydro Trimethylethanonaphthalenyl Methyl Ketone

INCI: HEXAHYDRO-TRIMETHYLETHANONAPHTHALEN-8-YL METHYL KETONE

A synthetic woody-amber fragrance ingredient that is generally considered safe at low concentrations but offers no skincare benefit.

beautyskincarefragrance

In plain English

This is a man-made chemical that smells like warm wood or amber. It's added to products like lotions and perfumes to give them a pleasant scent. It doesn't moisturize, treat, or improve your skin in any way—it's purely for fragrance.

Review score

Safety, usefulness, and evidence

3.5Good
3.5/ 5

Potentially useful with some tradeoffs

The evidence base is useful, but some claims depend heavily on the formula.

Risk flags are low for most users, though the finished product can still irritate.

Source
synthetic
Evidence
moderate
Irritation
low
Clogging risk
low
How reviews are scored

Quick decision guide

Useful, but context matters

Hexahydro Trimethylethanonaphthalenyl Methyl Ketone is generally a lower-concern ingredient when the full formula suits your skin.

Plain-English read

Treat this as a practical screening step before you compare products that contain this ingredient.

  1. Step 1Start with the score, then check the irritation and clogging risk before judging Hexahydro Trimethylethanonaphthalenyl Methyl Ketone.
  2. Step 2Use the "Best for" and "Use caution if" sections to match the ingredient to your skin, not just to a marketing claim.
  3. Step 3If a product stings, breaks you out, or worsens irritation, judge the finished formula and stop using it even if the ingredient scores well.

Score terms in plain English

Irritation risk

low

Less likely to sting, burn, or bother most users, though sensitive skin can still react.

Clogging risk

low

Less likely to feel heavy or contribute to clogged pores for most skin types.

Evidence level

moderate

There is useful support, but formula details and claim strength still matter.

What it is

A synthetic aromatic compound from the naphthalene family, created in a lab to mimic natural woody-amber notes. It is often listed under the trade name OTNE (Octahydro Tetramethyl Naphthalenyl Ethanone).

How it works

It evaporates from the skin's surface, releasing molecules that interact with olfactory receptors in your nose. In a cosmetic product, it simply provides a long-lasting, warm scent that helps mask the base odor of other ingredients.

Pros

Pleasant scent

Adds a warm, woody-amber fragrance that many find appealing and long-lasting on the skin.

Low irritation potential

At typical use levels, it has a low risk of causing skin irritation for most people.

Cons and cautions

No skincare benefit

This ingredient is purely for fragrance and does not hydrate, soothe, or improve skin health in any way.

Potential allergen

As a fragrance ingredient, it can trigger allergic reactions or irritation in individuals with fragrance sensitivities.

Best for

  • Anyone who enjoys a warm, woody scent in their products
  • Those without fragrance sensitivities looking for a long-lasting perfume note

Use caution if

  • People with fragrance allergies or sensitive skin that reacts to scented products

Usage tips

If you have sensitive skin, patch test any product containing this ingredient before full use.
Look for products that list this ingredient near the end of the INCI list, indicating a low concentration.

Safety summary

Generally recognized as safe at low concentrations by major cosmetic safety panels. However, it is a known fragrance allergen and can cause contact dermatitis in sensitive individuals. The evidence for systemic toxicity is low, but long-term environmental persistence is a concern.

Research notes

Research primarily focuses on its allergenicity and environmental persistence. It is not associated with significant skin irritation or sensitization in the general population, but patch test studies show it can cause reactions in fragrance-allergic individuals. Environmental studies indicate it is not readily biodegradable.

Common label clues

Typical concentration
Typically used at very low levels, often below 1% in leave-on products
Regulatory status
Approved for use in cosmetics in the US and EU. In the EU, it must be listed on the label if present above 0.01% in leave-on products or 0.001% in rinse-off products due to potential allergenicity.
Common uses
Fragranced skincare, Body lotions, Perfumes, Hair products
Environmental note
As a synthetic compound, it is not biodegradable and may accumulate in the environment. Some studies have detected it in waterways, raising ecological concerns.

Good to know

  • This ingredient is often listed under the trade name OTNE on fragrance ingredient lists.
  • It is considered a 'fragrance allergen' under EU cosmetics regulations and must be listed on the label if above certain concentrations.

Common questions

What is Hexahydro Trimethylethanonaphthalenyl Methyl Ketone in beauty products?

This is a man-made chemical that smells like warm wood or amber. It's added to products like lotions and perfumes to give them a pleasant scent. It doesn't moisturize, treat, or improve your skin in any way—it's purely for fragrance.

What does Hexahydro Trimethylethanonaphthalenyl Methyl Ketone do in a beauty product?

It evaporates from the skin's surface, releasing molecules that interact with olfactory receptors in your nose. In a cosmetic product, it simply provides a long-lasting, warm scent that helps mask the base odor of other ingredients.

Is Hexahydro Trimethylethanonaphthalenyl Methyl Ketone safe for most people?

Generally recognized as safe at low concentrations by major cosmetic safety panels. However, it is a known fragrance allergen and can cause contact dermatitis in sensitive individuals. The evidence for systemic toxicity is low, but long-term environmental persistence is a concern.

Who should be careful with Hexahydro Trimethylethanonaphthalenyl Methyl Ketone?

People with fragrance allergies or sensitive skin that reacts to scented products

Research sources

Ingredient reviews are educational and are not medical advice. Patch test new products and ask a licensed clinician about persistent irritation, allergies, pregnancy-specific questions, or diagnosed skin conditions.