At a glance:

  • ECHA added n-hexane (CAS 110-54-3) and bisphenol AF to the REACH SVHC Candidate List on 4 February 2026; the list now holds 253 entries.
  • n-hexane was listed under Article 57(f) via an equivalent level of concern for neurotoxicity, not the CMR route.
  • Article 33 supplier-communication duties applied from 4 February 2026; Article 7(2) notification to ECHA is due by 4 August 2026 above the 0.1% w/w and 1 t/yr thresholds.
  • The listing triggers information and notification obligations — it is not a ban, nor an automatic authorisation requirement under Annex XIV.
  • CPME (cyclopentyl methyl ether, CAS 5614-37-9) has an ICH Q3C(R8) Permitted Daily Exposure (PDE) from 2021, reaffirmed by ICH Q3C(R9) in 2024.
  • CHEM21 and recent Chem. Rev. literature position CPME as one of the defensible replacements for THF, MTBE, and 1,4-dioxane in API process chemistry.

Prepared by Easier Materials Regulatory Affairs. Reviewed by Easier Materials QA Department.

On 4 February 2026, the European Chemicals Agency added n-hexane to the REACH Substances of Very High Concern (SVHC) Candidate List under Article 57(f). The listing does not ban n-hexane in the EU, but it does start two compliance clocks that matter to pharmaceutical manufacturers, CDMOs, and their downstream customers. From the listing date, suppliers of articles that contain n-hexane above 0.1% w/w owe their recipients information on safe use under Article 33. By 4 August 2026, producers or importers of such articles above 1 tonne per year must submit a formal notification to ECHA under Article 7(2).

For API and fine-chemical process teams, the practical question is whether to keep n-hexane on the BOM and manage the documentation burden, or to substitute. Cyclopentyl methyl ether (CPME) has emerged as one defensible substitution pathway, with an ICH Q3C(R8) 2021 Permitted Daily Exposure (reaffirmed in Q3C(R9) 2024) and endorsement under the CHEM21 solvent-selection framework as a replacement for THF, methyl tert-butyl ether, and 1,4-dioxane. This article walks through the regulatory mechanics, the CPME comparison, and the documentation path for a clean substitution.

What did ECHA add to the SVHC Candidate List on 4 February 2026?

ECHA confirmed two additions on 4 February 2026, bringing the Candidate List total to 253 entries. n-hexane (EC 203-777-6, CAS 110-54-3) was listed under REACH Article 57(f) on the basis of specific target-organ toxicity on repeated exposure — explicitly peripheral neurotoxicity — identified via the equivalent level of concern (ELOC) route. This is the first time a substance has been added to the Candidate List on an ELOC/neurotoxicity rationale rather than the conventional CMR pathway. The second addition was 4,4'-[2,2,2-trifluoro-1-(trifluoromethyl)ethylidene]diphenol (bisphenol AF / BPAF) and its salts, listed under Article 57(c) for reproductive toxicity.

The listing rationale matters because it sets a precedent for how ECHA frames occupational and downstream-user exposure arguments. n-hexane's cited uses in the ECHA and industry dossiers include formulations, polymer processing, coatings, cleaning agents, and use as a solvent in pharmaceutical manufacture and food-grade vegetable-oil extraction. Process chemistry teams whose current documentation still references n-hexane as an extraction, Grignard co-solvent, or crystallisation solvent are directly in scope.

Importantly, SVHC listing is a precursor step. Annex XIV (the Authorisation List) and Annex XVII (restriction) are separate, later ECHA recommendations and Commission decisions. As of April 2026, no source indicates n-hexane has been recommended for Annex XIV. The article you are reading does not treat n-hexane as banned — it is not.

Which obligations trigger by 4 August 2026 — and for whom?

Two distinct REACH obligations flow from an SVHC listing. They apply from the listing date but have different scope, different recipients, and different thresholds.

Article 33 — Communication in the supply chain. Applied from 4 February 2026. Any supplier of an article (as defined by REACH) containing an SVHC above 0.1% w/w must provide sufficient information on safe use to business recipients automatically, and to consumers on request within 45 days, free of charge. There is no volume threshold. The duty is proactive to business customers; reactive to consumers.

Article 7(2) — Notification to ECHA. Due by 4 August 2026 (six months after listing). Producers and importers of articles containing an SVHC above 0.1% w/w, placed on the EU market in quantities exceeding 1 tonne per year, must submit a formal notification to ECHA via IUCLID. Exemptions apply where the substance is already registered for that use, or where exposure during normal and reasonably foreseeable use can be excluded.

For pharmaceutical manufacturers, the key question is whether your output is classed as a "substance" (active ingredient, bulk solvent), a "mixture" (formulated product), or an "article" (shaped object — e.g. pre-filled device, blister, finished packaging). Article-level obligations apply to articles; substances and mixtures sit under separate REACH provisions (Articles 31, 32, SDS, eSDS). An API or bulk intermediate with residual n-hexane above 0.1% w/w in a mixture triggers SDS obligations under Article 31 rather than Article 7(2). Confirm article vs. mixture classification with your regulatory function before filing.

Independent regulatory digests from Bureau Veritas CPS, iPoint Systems, Certivo, and Z2Data converge on the same timeline and thresholds — all published between 4 February and late February 2026 — and are cited in the references.

How does CPME compare to n-hexane in pharma process chemistry?

CPME is not a one-for-one replacement in every application, but it covers a large share of the common process roles — reaction solvent, Grignard / organometallic medium, and liquid-liquid extraction partner. The substitution case rests on three anchors: a formal ICH Q3C(R8) Permitted Daily Exposure, a CHEM21 green-solvent ranking, and a peer-reviewed literature base documenting process-scale performance.

The CPME product page summarises the grade Easier Materials supplies (≥99% purity, CoA per batch). For pharma deployment, the relevant process attributes are:

Attribute n-hexane CPME THF 2-MeTHF
CAS 110-54-3 5614-37-9 109-99-9 96-47-9
Boiling point (°C) 68.7 106 66 80
Water solubility (g/100 mL, 23 °C) ~0.001 (practically insoluble) 1.1 (slightly soluble) Miscible ~14
Peroxide formation tendency Negligible Low High Moderate–high
Water azeotrope (easy drying) Yes Yes Yes (minimum-boiling) Yes
ICH Q3C class Class 2 (PDE 290 mg/day) PDE assigned under Q3C(R8) 2021 Class 2 PDE assigned under Q3C(R8) 2021
REACH SVHC status (April 2026) Candidate List (listed 4 Feb 2026) Not listed Not listed Not listed
CHEM21 ranking Hazardous Problematic (yellow; manageable) Problematic Recommended

Three properties make CPME easier to adopt than its ethereal peers. CPME's peroxide formation rate is materially lower than THF's and 2-MeTHF's, reducing the need for frequent antioxidant dosing. The 106 °C boiling point gives wider reflux headroom than THF (66 °C) without pushing into DMF/NMP territory. And the water azeotrope enables straightforward drying and solvent recovery when a process moves from n-hexane to a more polar medium.

The peer-reviewed record supports these points. Chem. Rev. 2022 frames CPME as "a widely applicable replacement for tetrahydrofuran, methyl tert-butyl ether, dioxane, and other [ethereal] solvents." Asian J. Org. Chem. 2016 (Kobayashi et al.) documents Grignard reagents prepared and stored for months in CPME, with GC-MS confirming CPME stability under Grignard conditions.

CPME is not the only option. 2-MeTHF, Cyrene, and γ-valerolactone serve adjacent niches; CHEM21 positions them as a family. Easier Materials' position is that CPME is one ICH-recognised, literature-backed replacement candidate — not "the" answer.

What documentation do downstream users need to substitute cleanly?

A compliant CPME substitution in a regulated pharma workflow is a documentation exercise, not just a process-chemistry exercise. Expect your QA and regulatory functions to request the following before releasing a change control:

  • CoA per batch confirming ≥99% purity, residual water, peroxide level, and residual solvent profile. Easier Materials supplies CoA with every shipment.
  • MSDS / eSDS consistent with CLP and REACH Article 31, including exposure scenarios relevant to Grignard, lithiation, and extraction use.
  • ICH Q3C(R8)/(R9) residual-solvent declaration identifying CPME's PDE classification in the current revision.
  • Supplier qualification file — batch traceability, manufacturing-site GMP status where applicable, ISO 9001 certification.
  • Transport and hazard documentation — CPME ships as UN Class 3 flammable liquid (flash point –1 °C); confirm ADR/IMDG packaging and labelling with your freight partner.

For CMDOs and API manufacturers serving the EU market, a clean substitution project for pharmaceutical-industry workflows typically runs process-development screening → analytical method bridging (GC residual solvent, Karl Fischer water, NMR purity) → pilot-scale validation → change control filing. Plan 6–12 months for a non-trivial API substitution, and longer where the affected step sits in a registered process already referenced in a DMF or EU marketing authorisation dossier.

If CPME is in your substitution shortlist, request a quote with your required grade, volume, packaging, and delivery Incoterm. Standard lead time from order confirmation is 2–4 weeks; CPME production in China is concentrated among a small number of qualified producers, so advance planning for blanket contracts is advisable for recurring monthly demand.

Scenarios

Three buyer profiles illustrate how the 4 August 2026 deadline translates into procurement action.

Scenario A: An EU pharma CMO with active n-hexane workflows

If you operate an EU GMP facility currently using n-hexane in API extraction, dewaxing, or recrystallization steps, the 4 August 2026 deadline applies to you as a downstream user. Article 33 communication duties applied from the 4 February 2026 listing date; Article 7(2) notification is due by 4 August 2026 where article-level outputs cross the 0.1% w/w and 1 t/yr thresholds.

The practical work this quarter is an audit of n-hexane consumption across registered processes, identification of substitution candidates per the ICH Q3C class framework, and documentation of the substitution rationale alongside continued-use justifications where substitution is not feasible. Article/mixture/substance classification should be confirmed with the regulatory function before deciding which REACH provision governs.

CPME's positioning here rests on its formal ICH Q3C(R8) 2021 PDE and CHEM21 endorsement as one replacement for ethereal solvents. The defensible procurement action is to scope a process-development screening for the highest-volume n-hexane step and include CPME among the candidates evaluated.

Scenario B: A Japanese or Korean API exporter shipping to the EU

If you are a non-EU API manufacturer whose finished product enters the EU supply chain, your customers will request supplier declarations on n-hexane content from August 2026. SVHC obligations cascade through Article 33 from EU importers back to non-EU manufacturers via the supplier-declaration mechanism — the duty sits with the EU-side actor, but the documentation flow originates upstream.

EU customers will typically request residual-solvent profiles, batch-level CoA confirming n-hexane content against the 0.1% w/w threshold, and where applicable a substitution roadmap. CPME's ICH Q3C(R8/R9) PDE recognition simplifies the regulatory dossier because the residual-solvent declaration plugs directly into the existing Q3C framework.

CPME supply-chain maturity in Asia is concentrated among a small number of qualified producers. The defensible procurement action is to qualify a CPME supplier with documented ICH Q3C compliance ahead of customer requests.

Scenario C: An Indian generics or contract synthesis manufacturer

If you are an Indian API or contract synthesis house with EU export exposure, the SVHC listing affects you indirectly through customer specification updates rather than through direct REACH obligations. A workable timeline is to audit suppliers in Q2 2026, pilot CPME runs in Q3 2026, and target full substitution in Q4 2026 / Q1 2027 for affected steps.

Green-chemistry positioning is a customer-acquisition lever in this segment, and a documented CPME substitution capability supports that conversation. The n-hexane entry is also a precedent worth tracking — the first ELOC/neurotoxicity-route listing under Article 57(f), suggesting further solvent restrictions may follow. The defensible procurement action is to build substitution muscle now rather than under a future deadline.

Recent developments

References

Summary

The February 2026 SVHC listing of n-hexane does not prohibit its use in the EU. It does, however, activate Article 33 communication from the listing date and an Article 7(2) notification deadline of 4 August 2026 for producers and importers of articles above the 0.1% w/w and 1 t/yr thresholds. Pharmaceutical manufacturers whose workflows still rely on n-hexane for extraction, Grignard chemistry, or crystallisation should review their BOMs, confirm whether their EU-market outputs are classed as articles, mixtures, or substances, and decide whether to document continued use or substitute. CPME — with an ICH Q3C(R8) 2021 PDE, CHEM21 endorsement, and a well-developed peer-reviewed process-chemistry record — is one defensible substitution pathway among several. The next step for teams weighing substitution is a process-chemistry screening and a conversation with supply.

FAQ

Does the February 2026 SVHC listing mean n-hexane is now banned in the EU?

No. Inclusion on the SVHC Candidate List triggers information obligations under REACH Article 33 and, for producers and importers of articles above the 0.1% w/w and 1 t/yr thresholds, notification to ECHA under Article 7(2) by 4 August 2026. A use restriction would require either listing on Annex XIV (authorisation) or Annex XVII (restriction) — both of which are separate, later ECHA recommendations and European Commission decisions. As of April 2026, n-hexane is on the Candidate List only.

What is the 4 August 2026 deadline, exactly?

It is the Article 7(2) deadline for producers and importers of articles containing n-hexane or bisphenol AF above 0.1% w/w and placed on the EU market in quantities exceeding 1 tonne per year. Notification is submitted to ECHA via IUCLID. Article 7(2) applies to articles, not to substances or mixtures; the correct article/mixture/substance classification of your output determines which REACH provision governs.

Is CPME classified as ICH Q3C Class 3?

CPME received a formal Permitted Daily Exposure (PDE) under ICH Q3C(R8) in April 2021, reaffirmed in Q3C(R9) in 2024. Some secondary sources summarise CPME's behaviour as Class-3-like (≤50 mg/day without further justification), but for a regulatory filing, confirm the exact class and PDE value against the current Q3C(R9) Appendix 2 table directly before publication of your own specification.

Is CPME the only acceptable replacement for n-hexane in pharma processes?

No. CHEM21 and the Chem. Rev. 2022 review position CPME alongside 2-MeTHF, Cyrene, and γ-valerolactone as a family of greener-solvent candidates. CPME covers a large share of ethereal-solvent use cases — Grignard, lithiation, extraction, crystallisation — and has the advantage of a formal ICH PDE, lower peroxide formation than THF/2-MeTHF, and a water azeotrope for easy drying. Selection should be driven by process requirements, existing analytical method fit, and the substitution evidence base for your specific chemistry.