At a glance
| Chemical family | A polycyclic synthetic musk (fragrance); trade name Tonalide. The sibling of HHCB, with which it dominates the synthetic-musk market |
| CAS number | 1506-02-1 |
| Classification | Restricted in EU cosmetics under Annex III (safe within set limits after SCCS assessment). Bioaccumulative; more toxic to aquatic organisms than HHCB |
| Where you encounter it | Perfumes, cosmetics, and perfumed laundry detergents and softeners. The bedroom route is fabric deposition from scented laundry, plus transfer from skin-applied scented products |
| Sleep micro-environment relevance | Designed to persist on fabric; bioaccumulative and found in human breast milk (second to HHCB). Measured levels have been declining over time |
| Activated carbon capture | Not the lever — fragrance-free laundry and personal-care products remove it at the source |
What it is
AHTN is a polycyclic synthetic musk — a lab-made fragrance molecule that, with HHCB, replaced the natural and nitro musks of earlier eras. The two are the workhorses of modern scent, used across perfumes, cosmetics and household products. Regulatory — EU Cosmetics Regulation, Annex III Functionally it behaves almost identically to its sibling, which is why this page is shorter: the bedroom story is the same one told on the HHCB page, with a few meaningful differences in the regulatory and environmental detail.
Like HHCB, AHTN is built to last on fabric and is bioaccumulative. In a study of synthetic musks in mothers' milk, AHTN was the second-most abundant musk after HHCB, and — the detail that matters for sleep — elevated AHTN was associated specifically with the use of perfumed laundry detergent. Peer-reviewed — Lignell et al. 2008
How it relates to the bedroom
The same laundry-and-skin pathway
AHTN gets onto bedding the two ways HHCB does: it is added to perfumed detergents and fabric softeners that are designed to leave scent on fabric, so it persists on sheets and pillowcases through repeated nights of skin contact; and it transfers from scented skin and hair products used before bed. The breast-milk association with perfumed laundry detergent makes the laundry route concrete. Peer-reviewed — Lignell et al. 2008 Everything said about the personal-care exposure pattern on the HHCB page applies here.
Where it differs from HHCB
Three differences are worth stating, because they shape the honest verdict. First, regulation: AHTN is restricted — not banned — in EU cosmetics under Annex III, meaning regulators have set conditions (such as maximum concentrations) under which its use is considered safe. Regulatory — EU Cosmetics Regulation, Annex III entry 182 Second, trend: breast-milk monitoring found AHTN concentrations declining significantly over the years studied, suggesting reduced industrial use — a more encouraging trajectory than HHCB, whose levels did not fall in the same study. Peer-reviewed — Lignell et al. 2008 Third, environment: AHTN is somewhat more toxic to freshwater and marine organisms than HHCB, so its clearest documented harm is ecological. Peer-reviewed — Li et al. 2021
The calm verdict
Taken together: AHTN is a bioaccumulative fragrance that ends up on your bedding and in your body, which is reason enough to reduce avoidable exposure — especially during pregnancy and nursing, given the breast-milk findings. But it sits within EU cosmetic limits, its use has been trending down, and its strongest evidence of harm is to aquatic life rather than to people at current exposure levels. Inferred — weighing the bioaccumulation against the regulatory limits, declining trend, and predominantly ecological toxicity A reduce-where-easy compound, handled by the same fragrance-free choices as its sibling.
What the research says
- It is bioaccumulative. Second-most abundant musk in human breast milk after HHCB. Peer-reviewed — Lignell et al. 2008
- Perfumed laundry detergent is a documented source. Elevated AHTN tracked with its use. Peer-reviewed — Lignell et al. 2008
- Its use has been declining. Breast-milk levels fell over the monitoring period. Peer-reviewed — Lignell et al. 2008
- It is EU-restricted and aquatically toxic. Annex III cosmetic limits; more toxic to aquatic organisms than HHCB. Regulatory — EU Annex III Peer-reviewed — Li et al. 2021
What helps reduce it
Wash bedding in fragrance-free detergent. The most effective bedroom step, since laundry fragrance is meant to stay on the fabric you sleep against. Peer-reviewed — Lignell et al. 2008
Skip scented fabric softener and dryer sheets. Their purpose is to deposit fragrance — including musks — onto fabric. Inferred — softeners and dryer sheets deposit fabric fragrance by design
Use fragrance-free skin and hair products at bedtime. The skin route is the dominant exposure pathway for synthetic musks generally. Peer-reviewed — Luo et al. 2023
What does NOT help
- Trusting "unscented." Masking musks are often added to "unscented" products; the meaningful label is "fragrance-free." Inferred
- Air purifiers. AHTN arrives on fabric and skin, not as an air pollutant to be filtered. Inferred
Open research questions
- Whether the decline in AHTN body burden has continued since the mid-2000s, and how it now compares with HHCB. Speculation
- The real-world transfer of AHTN from fragranced bedding to skin over a night's sleep. Speculation
Citations
- Lignell S, et al. (2008). Temporal trends of synthetic musk compounds in mother's milk and associations with personal use of perfumed products. Environmental Science & Technology. AHTN second to HHCB in breast milk; elevated AHTN with perfumed laundry detergent; AHTN declined 1996–2003. Via Consensus. Reference record Peer-reviewed
- Li W, et al. (2021). Derivation of predicted no effect concentration and ecological risk assessment of polycyclic musks tonalide and galaxolide in sediment. Ecotoxicology and Environmental Safety. AHTN and HHCB persistent/bioaccumulative; AHTN more toxic to aquatic organisms than HHCB. Via Consensus. Reference record Peer-reviewed
- EU Cosmetics Regulation (EC) No 1223/2009, Annex III entry 182 — Acetyl Hexamethyl Tetralin (AHTN / Tonalide). Restricted under set conditions following SCCS assessment; safe within those limits. Documented in the Cosmetics Europe COSMILE database. cosmileeurope.eu Regulatory
Frequently asked questions
What is AHTN, and how is it different from HHCB?
AHTN — trade name Tonalide — is a synthetic polycyclic musk, and together with HHCB (Galaxolide) it makes up the large majority of polycyclic musks used in consumer products. The two are siblings with the same role and the same bedroom pathway: fragrance in perfumes, cosmetics and laundry products that deposits on fabric and skin. The main differences are regulatory and environmental — AHTN is restricted in EU cosmetics under Annex III, its measured use has been declining, and it is somewhat more toxic to aquatic life than HHCB.
How does AHTN get onto my bedding?
The same two ways HHCB does. It is added to perfumed laundry detergents and fabric softeners, which are designed to leave fragrance on fabric, so it persists on sheets and pillowcases; and it transfers from scented skin and hair products applied before bed. A breast-milk study found elevated AHTN specifically among women who used perfumed laundry detergent, which makes the laundry route concrete rather than theoretical.
Is AHTN dangerous?
Like its sibling, AHTN is bioaccumulative and is detected in human breast milk and tissue, so it is reasonable to reduce avoidable exposure — particularly during pregnancy and nursing. It is restricted (not banned) in EU cosmetics under Annex III, meaning regulators consider it safe within set limits. Encouragingly, breast-milk monitoring showed AHTN levels declining over time, suggesting reduced use. Its clearest documented harm is environmental: it is more toxic to aquatic organisms than HHCB.
How do I reduce AHTN exposure?
Exactly as for HHCB: wash bedding in fragrance-free detergent, skip scented fabric softener and dryer sheets, and choose fragrance-free skin and hair products for use before bed. Remember that "unscented" products can still contain masking musks — "fragrance-free" is the label that signals no added fragrance.
Related compounds
Embr is a sleep environment company researching and addressing the chemistry of the bedroom. Research and product development in progress.
Last reviewed 2026-06-27. If you find a factual error, contact us.