At a glance
| Chemical family | Synthetic musk — polycyclic musk replacement (octahydrotetramethyl naphthalenyl ethanone) |
| CAS number | 54464-57-2 |
| Classification | Not classified by IARC. EU SCCS safety assessment completed (considered safe in cosmetics at current use levels). Endocrine-disrupting potential under investigation. ECHA registered under REACH |
| Where you encounter it | Fragranced laundry detergents, fabric softeners, and dryer sheets; perfumes and body sprays; scented candles and air fresheners; household cleaners; indoor air and house dust |
| Sleep micro-environment relevance | Transfers to bedding from fragranced laundry products — sheets, pillowcases, and pyjamas washed with OTNE-containing detergent carry the fragrance into the sleep environment. One of the most abundant synthetic fragrance chemicals in bedroom air |
Regulatory & certification status
| European Union | REACH registered substance. SCCS safety assessment concluded OTNE is safe in cosmetics at up to 2.3% in leave-on and up to 11.5% in rinse-off products. CLP Skin Sens. 1B (H317). Not on the SVHC candidate list. Regulatory |
| United States | Not specifically regulated by FDA in cosmetics. Fragrance ingredients are not required to be individually listed on US product labels (listed as 'fragrance' or 'parfum'). IFRA (industry body) sets voluntary usage standards. Industry |
| Canada | Not specifically restricted. Health Canada does not individually regulate fragrance ingredients in cosmetics. Regulatory |
| International | Not IARC classified. IFRA (International Fragrance Association) sets industry standards for safe use levels. EU SCCS assessment is the most comprehensive regulatory evaluation. Regulatory |
What it is
OTNE is a synthetic musk with a woody, amber, cedarwood-like scent profile. It was developed as a high-performance fragrance ingredient with better biodegradability than the older polycyclic musks HHCB (Galaxolide) and AHTN (Tonalide). OTNE has become the dominant synthetic musk by volume, used across personal care products, household cleaning products, and fine fragrance. IARC has not evaluated OTNE. The EU SCCS assessed OTNE for safety in cosmetics and concluded it was safe at current use levels, though it noted that OTNE can cause skin sensitisation at higher concentrations. Endocrine-disrupting potential has been investigated in several in vitro studies — some have reported weak estrogenic and anti-androgenic activity, but the biological significance at human-relevant exposures is not established. OTNE is detected in indoor air, house dust, and wastewater.
Where it shows up in bedding
OTNE enters the bedroom primarily through fragranced laundry products. When sheets, pillowcases, duvet covers, and pyjamas are washed with OTNE-containing detergent or fabric softener, the fragrance adsorbs to the textile fibres and persists through drying and storage. During sleep, OTNE off-gasses from the warm fabric surface into the breathing zone — this is, in fact, its intended function as a fragrance (the scent of 'clean sheets'). OTNE is also present in bedroom air from scented candles, plug-in air fresheners, and perfumes applied before bed. For people who use unscented or fragrance-free laundry products, OTNE levels on bedding are negligible. Switching to fragrance-free laundry products is the single most effective way to reduce synthetic musk exposure during sleep.
Citations
- EU SCCS (2012). Opinion on OTNE (1-(1,2,3,4,5,6,7,8-octahydro-2,3,8,8-tetramethyl-2-naphthalenyl)ethan-1-one). SCCS/1479/12. Source Regulatory
- Homem, V. et al. (2015). Occurrence and fate of synthetic musks in the aquatic environment. Water Research, 77: 58-72. Source Peer-reviewed
- Roosens, L. et al. (2007). Exposure to Synthetic Musks through Personal Care and Household Products. Chemosphere, 69(10): 1540-1547. Source Peer-reviewed
Frequently asked questions
Is the smell of clean sheets actually OTNE?
In many cases, yes. The 'fresh laundry' scent that persists on sheets and pillowcases after washing is largely composed of synthetic musks, with OTNE being the dominant ingredient in most modern formulations. These fragrance chemicals are engineered to adsorb to textile fibres and release slowly. If you prefer truly unscented bedding, switch to fragrance-free detergent.
Is OTNE safer than the older synthetic musks?
OTNE was developed partly to address the environmental persistence and bioaccumulation of older musks like HHCB and musk xylene. It is more biodegradable than the polycyclic musks and does not bioaccumulate to the same degree. However, concerns about endocrine-disrupting potential persist — in vitro studies have reported weak estrogenic activity. Whether OTNE is meaningfully safer for human health at real-world exposures is not fully resolved.
Related compounds
Embr is a sleep environment company researching and addressing the chemistry of the bedroom. Research and product development in progress.
Last reviewed 2026-07-08. If you find a factual error, contact us.