CAS 7783-06-4 · REACH · European Union

Hydrogen sulfide (H2S) under REACH

H2S · 硫化氢

Status: Registered. Hydrogen sulfide is fully registered under REACH. **Distinguishing pattern: Sour-gas natural occurrence + refinery / petrochemical / pulp-mill / sewage-treatment by-product; commercial merchant H2S is rare (captive feed to Claus-process sulfur recovery batch 80 dominates) + completes sulfur chain alongside elemental sulfur batch 80 plus H2SO4 batch 2 (H2S → S → SO2 → SO3 → H2SO4 Claus-then-contact chain) + chemical synthesis intermediate (mercaptans + thiophenes + sulfides + carbon disulfide CS2 captive) plus heavy-water D2O production (Girdler sulfide / GS process, declining) plus pulp-mill Kraft chemistry by-product downstream chains + high hazard profile (Acute Tox. 2 inhalation + Flam. Gas 1A + Press. Gas + Aquatic Acute 1 per harmonised CLP entry; verify exact harmonised classification against ECHA Annex VI to CLP Table 3.1 before relying).** NOT SVHC. NOT Annex XIV. NOT subject to AD/CVD measures (H2S is not a tradable customs commodity at scale; captive intermediate destruction via Claus-process sulfur recovery dominates).

Hydrogen sulfide is fully REACH-registered with **high hazard profile** (Acute Tox. 2 inhalation + Flam. Gas 1A + Press. Gas + Aquatic Acute 1; UN 1053 Class 2.3 + 2.1). NOT SVHC, NOT Annex XIV. NO AD/CVD. **Merchant H2S rare; captive Claus-process feed dominates** at sour-gas + refinery + pulp-mill operations. **Completes sulfur chain alongside elemental S + H2SO4**. EU Industrial Emissions Directive permit at point-source emitter facilities.

Listing and threshold

Substance Hydrogen sulfide (H2S) (CAS 7783-06-4), H2S
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

  • Acute Tox. 2 (inhalation): H330 per harmonised CLP entry (verify against ECHA Annex VI to CLP Table 3.1 before relying)
  • Flam. Gas 1A: H220
  • Press. Gas (compressed) UN 1053 OR Press. Gas (refrigerated liquefied)
  • Aquatic Acute 1: H400 + Aquatic Chronic 1
  • GHS pictograms: GHS02 (flame), GHS04 (gas cylinder), GHS06 (skull and crossbones), GHS09 (environment)
  • IARC: Not classified
  • NOT subject to Drug Precursors or Explosives Precursors scheduling
  • ADR / RID: UN 1053 Class 2.3 (toxic gas) + subsidiary risk 2.1 (flammable gas)

Restrictions and conditions of use

  • NOT on REACH Annex XIV (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
  • NOT subject to EU AD/CVD
  • NOT in CBAM Phase 1 scope
  • EU Industrial Emissions Directive (Directive 2010/75/EU) governs H2S emissions from refineries / petrochemical / pulp-mill installations (verify against EUR-Lex before relying)

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). **H2S is rarely traded as merchant cargo; it is captive intermediate destruction via Claus-process sulfur recovery at sour-gas plants + refineries**. Major Chinese H2S captive sources at Sinopec + CNPC + CNOOC sour-gas / refinery operations (verify each producer-site pair against the producer's public website before relying).

Required documents

  • REACH registration number on EU side
  • SDS (Acute Tox. 2 inhalation + Flam. Gas 1A + Press. Gas + Aquatic Acute 1 hazard profile)
  • Customs entry HS code 281110 (hydrogen sulfide / sulfides / sulfites)
  • ADR documentation for UN 1053 Class 2.3 + 2.1
  • Industrial Emissions Directive permit at point-source emitter facilities

Common compliance traps

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

  • **Sour-gas natural occurrence + refinery / petrochemical / pulp-mill / sewage-treatment by-product; merchant H2S rare (captive Claus-process feed dominates)**
  • **Completes sulfur chain alongside elemental sulfur batch 80 + H2SO4 batch 2** (H2S → S → SO2 → SO3 → H2SO4 Claus-then-contact)
  • Acute Tox. 2 inhalation + Flam. Gas 1A + Aquatic Acute 1 hazard profile
  • NOT SVHC, NOT Annex XIV, NO AD/CVD
  • **Chemical synthesis intermediate (mercaptans + thiophenes + sulfides + CS2 captive) + heavy-water D2O production (Girdler sulfide GS process, declining) + pulp-mill Kraft chemistry by-product downstream chains**
  • Major Chinese sources (sour-gas / refinery captive): Sinopec + CNPC + CNOOC
  • EU Industrial Emissions Directive permit at point-source emitter facilities

Where to read next

For substance-level identifiers (formula, molecular weight, SMILES, InChIKey), GHS hazard profile, IMDG transport class, and full sourcing reference for hydrogen sulfide (h2s), see the CAS 7783-06-4 sourcing reference.

For grade-by-grade buying notes, freight maths, supplier-tier pricing, and a worked landed-cost example, the hydrogen sulfide (h2s) 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

Referenced in

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