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Isoprene

CAS 78-79-5 · 100/100 · High conf.

Also registered as 7 other CAS numbers

9006-04-6 · 9041-65-0 · 26796-44-1 · 78006-92-5 · 823271-95-0 · 2378489-72-4 · 2706608-31-1

Isoprene chemical structure

Concern score

100/100Critical concern driven by cmr.
High confidence

Isoprene in plain language

What it is

Also known as Isoprene (stabilized); (2-Methyl-1,3-butadiene) · .beta.-methylbivinyl · 2-Methylbuta-1,3-diene · 1,3-Butadiene, 2-methyl- · 2-Methyl-1,3-Butadiene · 2-Methylbutadiene

Show all 16 names

2-Methyldivinyl · 3-Methyl-1,3-butadiene · BUTA-1,3-DIENE, 2-METHYL- · Isopentadiene · Isopren · Methyl bivinyl · Natural rubber · isoprene (sara iii) · isopreno · isoterpene

What it does

We don't have a plain-language description for Isoprene yet.

Recorded functional uses: Olefins/unsaturated

Is it a concern?
Critical concern: classified for carcinogenic, mutagenic or reproductive toxicity (CMR). It is banned in EU cosmetics.

Why it's flagged

  • Cmr

Isoprene (stabilized); (2-Methyl-1,3-butadiene) 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
  • Beauty
  • Industrial
  • EUEC

    Annex II of EU Cosmetics Regulation (EC) 1223/2009: substances prohibited in cosmetic products. CMR: Carcinogenic Cat. 1B(),Mutagenic Cat. 2()

    banned
    View source →
  • EUCosIngActiveCosmetics Regulation annex II / ref 1138.
    • Cosmetics Regulation annex II / ref 1138.Source →
  • USEPAcommercial use observedEPA CPDat observed this chemical in 12 composition records across product categories including Laboratory supplies, Road vehicles, Personal care. EPA CPDat classifies this chemical for functional uses including olefins/unsaturated.
    • EPA CPDat observed this chemical in 12 composition records across product categories including Laboratory supplies, Road vehicles, Personal care. EPA CPDat classifies this chemical for functional uses including olefins/unsaturated.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 Isoprene. 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 Isoprene 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 2010-10-15

    Open →
  • EPA Chemical and Products Database

    exposure · updated jan 24 1989

    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.

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 Isoprene in a product composition. These are source records, not Greenveil catalog products.

Source records

12

Named organisations

6

Laboratory suppliesRoad vehiclesPersonal careIndustrial machinery

Typical roles

Olefins/unsaturated
See products using Isoprene →