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Hymexazol

CAS 10004-44-1 · 100/100 · High conf.

Also registered as 4 other CAS numbers

29412-88-2 · 52229-82-0 · 128907-24-4 · 1135441-31-4

Hymexazol chemical structure

Concern score

100/100Critical concern based on regulatory listings.
High confidence

Hymexazol in plain language

What it is

Also known as Hymexazol (ISO); 3-hydroxy-5-methylisoxazole · 5-Methyl-1,2-oxazol-3(2H)-one · 5-methyl-1,2-oxazol-3-one · 3(2H)-Isoxazolone, 5-methyl- · 3-Isoxazolol, 5-methyl- · 3-hydroxy-5-methylisoxazole

Show all 19 names

5-METHYLISOXAZOL-3-OL · 5-Methyl-3(2H)-isoxazolone · 5-Methyl-3-hydroxyisoxazole · 5-Methyl-isoxazol-3-ol · 5-methylisoxazol-3(2H)-one · 5-methylisoxazol-3-one · F-319 · Hydroxyisoxazole · Hymexazole · Itachigarden · RTY-319 · SF-6505 · Tachigaren

What it does

Used in consumer products as a preservative.

  • Preservative
Is it a concern?
Critical concern: no hazard classifications on record. It is banned in EU cosmetics.

Why it's flagged

Hymexazol (ISO); 3-hydroxy-5-methylisoxazole is prohibited in cosmetic products under Annex II of the EU Cosmetics Regulation (EC) 1223/2009.

RestrictedEU EC — banned

The score describes this ingredient's chemical identity — its hazard profile from published classifications and regulatory status — not the safety of any product it appears in.

Regulation

Restrictions first, then routine listings from published regulatory sources.

  • EU Annex II — prohibited
  • EU prohibited in cosmetics

Recorded in these product areas

  • Found in consumer products
  • Industrial
  • EUEC

    Annex II of EU Cosmetics Regulation (EC) 1223/2009: substances prohibited in cosmetic products.

    banned
    View source →
  • EUCosIngActiveCosmetics Regulation annex II / ref 1678.
    • Cosmetics Regulation annex II / ref 1678.Source →
  • USEPAcommercial use observedEPA CPDat observed this chemical in 0 composition records across product categories including unclassified products. EPA CPDat classifies this chemical for functional uses including Preservative.
    • EPA CPDat observed this chemical in 0 composition records across product categories including unclassified products. EPA CPDat classifies this chemical for functional uses including Preservative.Source →
  • USFDAlisted in openFDA substanceopenFDA substance registry classifies this ingredient as chemical.
    • openFDA substance registry classifies this ingredient as chemical.Source →

Expert safety opinions

No expert opinion on file for Hymexazol. These are the independent scientific bodies that assess ingredients like this one; we show an opinion only when a record we hold cites it.

  • SCCS

    EU Scientific Committee on Consumer Safety

    No SCCS opinion on file.

  • CIR

    Cosmetic Ingredient Review (US expert panel)

    No CIR safety assessment on file.

Evidence & sources

No graded research studies for Hymexazol yet. This record is compiled from the published data sources below — registries and regulatory listings, not study findings.

7 data sources

Where this comes from

  • CosIng

    regulatory · updated 2026-09-23

    Open →
  • EU CosIng Cosmetics Regulation Annexes

    regulatory · updated 2021-11-03

    Open →
  • EPA Chemical and Products Database

    exposure · updated 2019-06-07

    Open →
  • EPA DSSTox Identifiers

    chemistry · updated 2025-12-29

    Open →
  • FDA GSRS UNII

    registry · updated 2026-02-26

    Open →
  • openFDA Substance

    registry · updated 2026-05-24

    Open →
  • PubChem Live Enrichment

    chemistry · updated 2026-05-17

    Open →

Suitability

Context-specific fit derived from published classifications and the current ingredient evidence profile.

Food use

Food-use source coverage is present in the current record.

Good fit

The ingredient appears in food-oriented source coverage or allowed-use references, which makes food use easier to support than a context with no domain signal at all.

Fragrance avoidance

No fragrance-linked caution surfaced in the current profile.

Good fit

This ingredient does not currently read as a fragrance-linked driver in the published evidence and hazard profile.

Where it has been recorded

How often EPA CPDat has listed Hymexazol in a product composition. These are source records, not Greenveil catalog products.

Named organisations

3

Typical roles

Preservative
See products using Hymexazol →