At a glance
| Chemical family | Alkylphenol — APE surfactant degradation product (endocrine disruptor) |
| CAS number | 140-66-9 |
| Classification | EU SVHC (endocrine disruptor). REACH Annex XVII Entry 46 restricts use. Not IARC classified. Estrogenic activity demonstrated in vitro and in vivo |
| Where you encounter it | Textile processing residues on imported fabrics; wastewater from textile manufacturing; degradation product of alkylphenol ethoxylate (APE) surfactants; house dust from treated textiles |
| Sleep micro-environment relevance | Residues on imported textiles used in bedding. Washing new bedding before use reduces residual octylphenol. Related to nonylphenol (same chemical class) |
Regulatory & certification status
| European Union | SVHC (identified as endocrine disruptor). REACH Annex XVII Entry 46 restricts 4-tert-octylphenol and its ethoxylates — not to be placed on the market in concentrations ≥0.1% in mixtures for specified uses. OEKO-TEX Standard 100 restricts alkylphenols in textiles. Regulatory — European Union authority |
| United States | EPA included nonylphenol and octylphenol in the TSCA work plan. No specific consumer textile restriction. EPA aquatic life criteria exist. Regulatory |
| Canada | Environment and Climate Change Canada assessed alkylphenols. CEPA-toxic for nonylphenol; octylphenol under related assessment. Regulatory |
| International | Not IARC classified. EU SVHC (endocrine disruptor). OSPAR priority substance for marine protection. Greenpeace Detox campaign targeted APE use in textile supply chains. Industry |
What it is
4-tert-Octylphenol is a branched-chain alkylphenol that results from the environmental degradation of octylphenol ethoxylate (OPE) surfactants. APE surfactants are used in textile processing (scouring, dyeing, finishing) because of their excellent wetting and emulsifying properties. When these surfactants degrade in wastewater treatment or in the environment, they lose their ethoxylate chains and convert to the parent alkylphenol — which is more persistent, more toxic, and more endocrine-disrupting than the parent ethoxylate. 4-tert-Octylphenol has been shown to bind estrogen receptors and induce estrogenic responses in both in vitro and in vivo studies. The EU identified it as an SVHC based on its endocrine-disrupting properties and restricted its use under REACH.
Where it shows up in bedding
4-tert-Octylphenol can be present as a residue on textiles — including sheets, pillowcases, and mattress covers — that were processed using APE surfactants during manufacturing. This is most relevant for imported textiles from regions where APE surfactant use in textile processing has not been restricted. The residue is on the fabric surface and can be substantially reduced by washing new bedding before first use. Over multiple washes, residual octylphenol is removed. For bedding manufactured under EU REACH or OEKO-TEX certified supply chains, octylphenol residues should be below detection limits.
The Embr Exposure Ledger: 4-tert-Octylphenol
One chemical, several public questions, answered from independent datasets and joined here — the environment it shows up in, the body burden it carries, how it is regulated, and what actually reduces it.
Detection and body-burden figures are occurrence data, not a personal measurement or a health diagnosis. Part of the Embr Exposure Ledger — an open, cross-dataset chemical join (download the data), reusable with attribution.
Citations
- ECHA. 4-tert-Octylphenol — Substance Information (SVHC). Source Regulatory
- White, R. et al. (1994). Environmentally Persistent Alkylphenolic Compounds Are Estrogenic. Endocrinology, 135(1): 175-182. Source Peer-reviewed
- EU REACH Annex XVII, Entry 46 — Alkylphenols restriction. Source Regulatory
Frequently asked questions
Should I wash new bedding before using it?
Yes. Washing new bedding before first use removes not only octylphenol and nonylphenol surfactant residues but also other processing chemicals (formaldehyde finishes, dye auxiliaries, sizing agents). This is standard advice from consumer safety agencies regardless of where the bedding was manufactured.
How is octylphenol different from nonylphenol?
Both are alkylphenols with estrogenic activity — degradation products of the surfactants used in textile processing. Nonylphenol is more widely studied and more widely restricted (it has its own Atlas entry). Octylphenol has similar endocrine-disrupting properties but is used in lower volumes. Both are EU SVHCs and both are restricted under REACH.
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.