chem-data European chemical and regulatory registry

Compound record

Antimony trioxide

1309-64-4 · synergist · flame retardant

flame retardantsynergistplastics
Dossier

Identity-first dossier for exact-name, CAS, and use-context lookups.

Lookup labels

Antimony sesquioxideAntimonious oxideDiantimony trioxide
Dossier Status Obligations Why Alternatives Changes Similar Sources
CAS 1309-64-4
Formula O3Sb2
Molecular weight 291.52 g/mol
InChIKey GHPGOEFPKIHBNM-UHFFFAOYSA-N

Current EU status

Regulatory snapshot for Antimony trioxide

Antimony trioxide is currently surfaced as no current candidate list row imported in the EU.

The current imported view anchors this substance in CandidateList. The live rationale focuses on No positive Candidate List entry captured in the current imported source set, and this page is designed for fast status checks before deeper source review.

Searchers usually land here for the chemical name, CAS number, abbreviation , and the question of whether the substance is tied to SVHC, REACH, POPs, or SCIP-style compliance work.

Why this page matters

Antimony trioxide is usually searched as a formulation component rather than a stand-alone regulatory topic. Teams land here when supplier paperwork says antimony oxide, antimony sesquioxide, or CAS 1309-64-4 and the real question is whether a flame-retardant package needs deeper EU review.

In chem-data it sits in flame-retardant, synergist, and plastics routes. That makes it a portfolio-screening substance for compounds, masterbatches, and finished materials rather than a simple one-list lookup.

The main SEO opportunity is exact-name lookup plus supply-chain interpretation: antimony trioxide uses, antimony oxide CAS number, and whether the substance is part of a broader declaration or substitution exercise.

No current Candidate List row importedcurrent statuslatest imported framework state
8 Mar 2026latest anchor datelisted, effective, or checked date

Identity

CAS, formula, aliases, and use context

Fast lookup

CAS 1309-64-4 · Formula O3Sb2 · Molecular weight 291.52 g/mol · Current status No current Candidate List row imported

If you landed here for formula, molecular weight, or exact substance identity, this block gives the shortest route before you branch into status, obligations, or sources.

CAS
1309-64-4
EC
215-175-0
Formula
O3Sb2
Molecular weight
291.52 g/mol
Primary class
synergist
Synonym count
89

Search-friendly summary

Antimony trioxide , CAS 1309-64-4, is tracked here as a flame retardant substance in the synergist class.

Common names and aliases

Antimony sesquioxideAntimonious oxideDiantimony trioxideANTIMONY TRIOXIDEExiteliteTimonox

What teams usually verify first

  • Is antimony trioxide acting as a synergist inside a halogenated flame-retardant formulation rather than as a stand-alone additive?
  • Which plastic, cable, or electronics-facing product families still depend on this synergist route?
  • Do customer declaration workflows require a source-backed EU status check even when no positive Candidate List row is imported?

What to do next

Use the right route for status, SCIP, and source questions

Status

Current legal state, Candidate List signals, and source-backed rationale

Go here for the framework answer block, listed dates, reasons, and the imported basis for the current EU status.

 Obligations

Who needs to act, what to check, and whether SCIP matters

Use this when the question is operational: SCIP, article communication, threshold review, portfolio screening, or substitute work.

 Why monitored

Why this substance is monitored in the EU

Use this when you want the hazard or legal basis behind the current status, not just the status label itself.

 Alternatives

Potential substitutes and nearby molecules

Use this to branch into lower-pressure neighbors, same-class analogs, and candidate-list peers.

 Changes

What changed over time

Use this when you want the timeline, not just the current state.

 Sources

Verify where the data came from

Use this when you need to audit provenance before trusting a claim.

Action prompts

Fast compliance and screening routes

Article duties

Check Candidate List threshold and SCIP relevance

Use this when the substance may sit in articles, components, or imported goods and you need to confirm communication and SCIP workflows.

 Portfolio review

Screen affected product families and formulations

The use profile suggests this substance can appear in materials portfolios where one listing can ripple across multiple SKUs, suppliers, or component bills.

 Source check

Verify the legal source before repeating the claim

Every summary should point back to the underlying authority surface. Use the source route when the exact notice, registry entry, or legal text matters.