CAS 7727-21-1 · REACH · European Union

Potassium peroxydisulfate (K2S2O8) under REACH

K2S2O8 · 过硫酸钾

Status: Registered. Potassium peroxydisulfate is fully registered under REACH. **Distinguishing pattern: produced by electrolysis of potassium bisulfate / sulfuric acid solution (K2SO4 + H2SO4 yields H2S2O8 + KHSO4, then crystallisation of K2S2O8); strong oxidiser. Major downstream uses: emulsion polymerisation initiator (acrylic + styrene-butadiene rubber SBR + styrene + vinyl acetate + acrylonitrile polymerisation, ~50 to 60% of global consumption) + electronic-industry etchant (printed circuit board cleaning + IC manufacture) + bleaching agent (cosmetics hair-bleaching + wood + textile) + total organic carbon (TOC) analyser reagent + organic-synthesis oxidant + emulsion-coating initiator. Resp. Sens. 1 H334 classification is the dominant occupational concern (notable for hairdresser asthma).** **EU AD measures on Chinese-origin persulfates (sodium + ammonium + potassium peroxydisulfate) under Regulation (EC) No 1184/2007 (provisional) + Regulation (EC) No 1192/2008 (definitive, 24 +) + extended via successor measures** (verify exact current measures + duty rates per producer against EUR-Lex https://eur-lex.europa.eu/ before invoicing); the cash-deposit rate at customs is the operative number, not the original investigation rate. NOT SVHC. NOT Annex XIV.

Potassium peroxydisulfate is fully REACH-registered with **Resp. Sens. 1 H334 classification (hairdresser asthma) + Ox. Sol. 3 + ATEX dust-explosion hazard**. **EU AD measures on Chinese-origin persulfates (Reg (EC) 1184/2007 + 1192/2008 + extended via successor measures); verify per producer + per persulfate type at EUR-Lex before invoicing**. NOT SVHC, NOT Annex XIV. **Emulsion polymerisation initiator ~50 to 60% + electronic-industry etchant + cosmetics hair-bleaching + TOC analyser downstream**. **Resp. Sens. 1 H334 + EU AD on persulfates are the practical EU-import compliance pivots.**

Listing and threshold

Substance Potassium peroxydisulfate (K2S2O8) (CAS 7727-21-1), K2S2O8
Regime EU Regulation (EC) No 1907/2006: Registration, Evaluation, Authorisation and Restriction of Chemicals
Jurisdiction European Union (EU-27 plus EEA: Iceland, Liechtenstein, Norway)
Status Registered
Tonnage threshold Registration required for any importer or manufacturer placing >1 t/year on the EU market

Classifications under this regime

  • Ox. Sol. 3: H272 + Skin Irrit. 2: H315 + Eye Irrit. 2: H319 + STOT SE 3: H335 + Acute Tox. 4 inhalation: H332 + Resp. Sens. 1: H334 + Skin Sens. 1: H317 per harmonised CLP (verify exact harmonised classification against ECHA Annex VI to CLP Table 3.1 before relying)
  • **Resp. Sens. 1 H334 classification is the dominant occupational concern; notable for hairdresser respiratory sensitisation / asthma**
  • IARC: Not classified (verify against https://monographs.iarc.who.int/ before relying)
  • ADR / RID: UN 1492 POTASSIUM PERSULFATE Class 5.1 (oxidiser) PG III (verify against current ADR at https://unece.org/transport/dangerous-goods/adr-2025-files before consigning)
  • **ATEX: dust-explosion hazard during handling + storage** (verify against EU Directive 2014/34/EU before relying)
  • **EU AD measures on Chinese-origin persulfates (sodium + ammonium + potassium peroxydisulfate) under Regulation (EC) No 1184/2007 + Regulation (EC) No 1192/2008 + extended via successor measures** (verify exact current measures + duty rates per producer against EUR-Lex https://eur-lex.europa.eu/ before invoicing)

Restrictions and conditions of use

  • NOT on REACH Annex XIV authorisation list (verify against ECHA https://echa.europa.eu/authorisation-list)
  • NOT classified as SVHC (verify against ECHA https://echa.europa.eu/candidate-list-table)
  • NOT subject to any Annex XVII restriction
  • **EU AD measures on Chinese-origin persulfates (Reg (EC) No 1184/2007 + 1192/2008 + successor measures); verify per producer against EUR-Lex before invoicing**
  • NOT in CBAM Phase 1 scope

Importer obligations

A non-EU producer cannot register directly under REACH. The EU importer of record must hold a registration or rely on an Only Representative (OR). **AD/CVD scope determination per persulfate type + per producer at EUR-Lex.** Major non-Chinese producers: United Initiators (Germany Pullach + USA Helena AR), Mitsubishi Gas Chemical (Japan), Peroxychem / Evonik (USA + Belgium). Major Chinese persulfate producers (subject to ongoing or successor EU AD): Yatai Chemical (Liaoning) + Wuxi Honour (Jiangsu) + Hebei Jiheng + ABA Chemicals (Jiangyin) + Yatai Foshan; verify each producer-site pair against the producer's public website before relying.

Required documents

  • REACH registration number on EU side
  • SDS (Ox. Sol. 3 + Resp. Sens. 1 + Skin Sens. 1 + Acute Tox. 4 inhalation)
  • Customs entry HS code 283340 (peroxosulphates persulphates)
  • ADR transport documentation UN 1492 Class 5.1 PG III oxidiser
  • **EU AD duty declaration where Chinese-origin persulfate (verify current duty rate against EUR-Lex per producer)**
  • ATEX dust-explosion handling documentation

Common compliance traps

The pitfalls that have bitten importers on this lane in the past. None of these is theoretical.

  • **EU AD measures on Chinese-origin persulfates (Reg (EC) 1184/2007 + 1192/2008 + successor; verify per producer at EUR-Lex)**
  • **Resp. Sens. 1 H334 (hairdresser asthma) + Ox. Sol. 3 + ATEX dust-explosion hazard**
  • NOT SVHC, NOT Annex XIV
  • ADR UN 1492 Class 5.1 PG III oxidiser
  • **Emulsion polymerisation initiator ~50 to 60% of global consumption (acrylic + SBR + styrene + vinyl acetate + acrylonitrile polymerisation) + electronic-industry etchant (PCB cleaning + IC manufacture) + cosmetics hair-bleaching + textile + wood bleaching + TOC analyser downstream chains**
  • Major Chinese producers: Yatai Chemical Liaoning + Wuxi Honour Jiangsu + Hebei Jiheng + ABA Chemicals Jiangyin + Yatai Foshan

Where to read next

For substance-level identifiers (formula, molecular weight, SMILES, InChIKey), GHS hazard profile, IMDG transport class, and full sourcing reference for potassium peroxydisulfate (k2s2o8), see the CAS 7727-21-1 sourcing reference.

For grade-by-grade buying notes, freight maths, supplier-tier pricing, and a worked landed-cost example, the potassium peroxydisulfate (k2s2o8) cornerstone hub covers the full sourcing chain.

For the structure and history of REACH, see the REACH glossary entry.

Need cross-jurisdiction compliance support on this substance? Run it through the REACH / TSCA / IECSC / AICIS / K-REACH checker, or send us the substance and the destination and we will quote FOB China and CIF / DDP landed including the regulatory work on the destination side.

Read next

Cross-jurisdiction profile and sourcing references

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