Is Rhein safe in cosmetics?
Rhein has a safety rating of "MODERATE" in our database. EU status: permitted. US status: restricted.
Moderate
Cosmetic Ingredient
Rhein
Also known as: 1,8-dihydroxy-3-carboxyl anthraquinone, 4-10-00-04088, 2-Anthroic acid, 9,10-dihydro-4,5-dihydroxy-9,10-dioxo-, BRN 2222155, Cassic acid (+9 more)
INCI: RHEIN
Rhein (CAS 478-43-3) is a cosmetic cosmetic ingredient functioning as Skin Conditioning (anthraquinone compound found in rhubarb, cascara, senna). EU Regulation 1223/2009 status: permitted. Industrial safety data is also available in the chemical safety database. Same-CAS public records also appear in industrial chemical safety data.
View industrial chemical safety profile for CAS 478-43-3 →
Auto-generated CPSR Part A draft with source citations
Function
Skin Conditioning (anthraquinone compound found in rhubarb, cascara, senna)
Safety Rating
MODERATE
Chemistry & Identifiers
IUPAC Name
4,5-dihydroxy-9,10-dioxoanthracene-2-carboxylic acid
InChIKey
FCDLCPWAQCPTKC-UHFFFAOYSA-N
Regulatory Status
EU EU Status
permitted
US US Status
restricted
US Notes
Not specifically restricted for cosmetic use; regulated in drug context (laxative)
For full compliance data across multiple jurisdictions, use the Substance Compliance tool.
Safety Data
Margin of Safety, dermal absorption, and sensitization profile summaries for Rhein.
Calculate MoS for your specific formulation with the MoS Calculator.
ECHA REACH Registration
European Chemicals Agency REACH dossier and Substances of Very High Concern listing.
Registration Type
Intermediate
Tonnage Band
Intermediate use only
Substance Type
SUBSTANCE
SVHC Candidate
No
Function Categories & List Membership
Cosmetic/Chemical Function Categories
Biocide
Expert Verdict
Expert safety assessment and concern-level summary for Rhein.
Known Synonyms
1,8-dihydroxy-3-carboxyl anthraquinone
4-10-00-04088
2-Anthroic acid, 9,10-dihydro-4,5-dihydroxy-9,10-dioxo-
BRN 2222155
Cassic acid
Chrysazin-3-carboxylic acid
9,10-Dihydro-4,5-dihydroxy-9,10-dioxo-2-anthracenecarboxylic acid
1,8-Dihydroxyanthraquinone-3-carboxylic acid
EINECS 207-521-4
Monorhein
NSC 38629
Rheic acid
Rhubarb Yellow
UNII-YM64C2P6UX
Chemical Function
Biocide
Regulatory Lists
Canada; pharmaceutical
Frequently Asked Questions
Is Rhein allowed in the EU?
Rhein EU regulatory status: permitted. This is based on EU Regulation 1223/2009 and its amendments.
What does Rhein do in cosmetics?
Rhein functions as: Skin Conditioning (anthraquinone compound found in rhubarb, cascara, senna). It is classified as a cosmetic ingredient in our database. CAS number: 478-43-3.
Is Rhein used outside cosmetics?
Rhein also appears in industrial chemical safety data. The cross-vertical cards on this page render same-CAS public rows from the matched databases.
Compliance Tools
Check Rhein compliance across multiple jurisdictions:
Ingredient Decoder
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Substance Compliance
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MoS Calculator
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Heavy Metal Limits
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