Moderate Cosmetic Ingredient NOAEL Data

Acid Red 51 (Erythrosine)

Also known as: Spiro(isobenzofuran-1(3H),9'-(9H)xanthen)-3-one,3',6'-dihydroxy-2',4',5',7'-tetraiodo-, disodium salt, Erythrosine B, Ceplac, E 127, Erythrosine 3 (+15 more)

INCI: CI 45430

Acid Red 51 (Erythrosine) (CAS 16423-68-0) is a cosmetic cosmetic ingredient functioning as Cosmetic colorant. Reported NOAEL =25 mg/kg bw/day in Mouse (ToxValDB_ECHA_IUCLID); EU Regulation 1223/2009 status: prohibited. 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 16423-68-0 →

Auto-generated CPSR Part A draft with source citations
CAS Number
16423-68-0
View industrial chemical safety profile →
Function
Cosmetic colorant
Safety Rating
MODERATE

Chemistry & Identifiers

Formula
C20H8I4O5
MW
835.9 g/mol
EC Number
240-474-8
PubChem CID
3259
IUPAC Name
3',6'-dihydroxy-2',4',5',7'-tetraiodospiro[2-benzofuran-3,9'-xanthene]-1-one
InChIKey
OALHHIHQOFIMEF-UHFFFAOYSA-N
ChEBI: CHEBI:61000 UNII: 8TL7LH93FM Wikidata: Q27888290

Regulatory Status

EU EU Status prohibited
US US Status prohibited
US Notes De-listed for cosmetics in 1990. FD&C Red No. 3 was permanently listed only for food and ingested drugs; FDA revoked food authorization in early 2025.

For full compliance data across multiple jurisdictions, use the Substance Compliance tool.

Safety Data

Margin of Safety, dermal absorption, and sensitization profile summaries for Acid Red 51 (Erythrosine).

Calculate MoS for your specific formulation with the MoS Calculator.

Toxicological Studies

10 study endpoints found for Acid Red 51 (Erythrosine). NOAEL (No Observed Adverse Effect Level) values are used to calculate the Margin of Safety per SCCS methodology.

Endpoint Value Route Species Study Type Source
NOAEL =25 mg/kg bw/day oral Mouse reproduction developmental ToxValDB_ECHA_IUCLID
NOAEL =75 mg/kg bw/day oral Mouse reproduction developmental ToxValDB_ECHA_IUCLID
NOAEL =149 mg/kg bw/day oral Rat reproduction developmental ToxValDB_ECHA_IUCLID
NOAEL =251 mg/kg bw/day oral Rat chronic ToxValDB_ECHA_IUCLID
NOAEL =255 mg/kg bw/day oral Rat reproduction developmental ToxValDB_ECHA_IUCLID
NOAEL =472 mg/kg bw/day oral Rat developmental ToxValDB_ECHA_IUCLID
NOAEL =500 mg/kg bw/day oral Dog chronic ToxValDB_ECHA_IUCLID
NOAEL =641 mg/kg bw/day oral Rat chronic ToxValDB_ECHA_IUCLID
NOAEL =800 mg/kg bw/day oral Rat reproduction developmental ToxValDB_ECHA_IUCLID
NOAEL =1000 mg/kg bw/day oral Rat reproduction developmental ToxValDB_ECHA_IUCLID

EPA ToxValDB — Toxicity Values

10 toxicity values from EPA ToxValDB (aggregated from CCTE, HPV, ToxRefDB, IRIS, and other regulatory dossiers).

Endpoint Value Species Route Duration Source
ADI <=0.1 mg/kg Human oral - WHO JECFA ADI
NOAEL =125 mg/kg-day Rat oral - EFSA
NOAEL =1 mg/kg-day Human oral short-term EFSA
LOEL =100 mg/kg-day Mouse oral acute ECOTOX
NOEL =10 mg/kg-day Mouse oral acute ECOTOX
LD50 >2000 mg/kg Rat dermal acute ECHA IUCLID
LD50 =7100 mg/kg Rat oral - ECHA IUCLID
LD50 =1895 mg/kg Rat oral - ECHA IUCLID
LD50 =1264 mg/kg Mouse oral - ECHA IUCLID
LD50 =7400 mg/kg Rat oral - ECHA IUCLID

ECHA REACH Registration

European Chemicals Agency REACH dossier and Substances of Very High Concern listing.

Registration Type
Full
Tonnage Band
10 - 100 tonnes
Substance Type
SUBSTANCE
SVHC Candidate
No

Expanded Jurisdictional Detail

Additional regulatory detail beyond the 7-jurisdiction summary: Saudi SFDA, Korea MFDS, ASEAN ACD, Japan/Korea, Brazil/India, and cross-jurisdictional restriction entries.

Additional Jurisdictional Restrictions (2)
Jurisdiction Status Max % Product Type
CN permitted_colorant - All cosmetics (Class 1)
ASEAN permitted_colorant - All products

Additional Ingredient Properties

1 property record from structured ingredient metadata.

colorant
{"Common_Name": "D&C Red No. 22", "Chemical_Name": "Eosin YS", "CAS_Number": "17372-87-1", "Colorant_Type": "Synthetic Dye", "Approved_Uses": "All cosmetics", "Max_Concentration_%": "No limit", "EU_Status": "Approved", "US_FDA_Status": "Approved 21 CFR 74.322", "Notes": "Yellowish red"}

PubChem Annotations

Safety and regulatory annotations from PubChem (NCBI) aggregated sources.

Safety (1)
Carcinogen Classification
No indication of carcinogenicity to humans (not listed by IARC).
Source: Toxin and Toxin Target Database (T3DB)
Regulatory (2)
JECFA Evaluation
FD AND C RED No. 3 | 2018 | 0-0.1 mg/kg bw | The Committee concluded that the new data that have become available since the previous evaluation of erythrosine do not give reason to revise the ADI and confirmed the previous ADI of 0–0.1 mg/kg bw. | ">TRS 1014-JECFA 86/27 | FAS 77 JECFA 86/49
Source: Joint FAO/WHO Expert Committee on Food Additives (JECFA)
EU Food Improvement
Food additives
Source: EU Food Improvement Agents

Function Categories & List Membership

Cosmetic/Chemical Function Categories
Dye Solvent
Regulatory List Membership (2)
EU Restricted for Children (Cosmetics) FDA Substances Added to Food (EAFUS)

Expert Verdict

Expert safety assessment and concern-level summary for Acid Red 51 (Erythrosine).

Regulatory Flags

colorant eu_children_restricted fda_food_additive

NOAEL Studies Summary

View details ->

Public NOAEL study rows linked to Acid Red 51 (Erythrosine) by CAS number or substance name.

Studies
14
Lowest NOAEL
25 mg/kg bw/day
Highest NOAEL
4579 mg/kg bw/day
ToxValDB_ECHA_IUCLID

Known Synonyms

Spiro(isobenzofuran-1(3H),9'-(9H)xanthen)-3-one,3',6'-dihydroxy-2',4',5',7'-tetraiodo-, disodium salt Erythrosine B Ceplac E 127 Erythrosine 3 Erythrosine E 127 Erythrosine Red 3 FDC Red 3 Food Red 3 Japan Food Red No. 3 Japan Red 3 Japan Red No. 3 Red 1799 Red 3 Red No. 3 C.I. ACID RED 51, (ERYTHROSIN B) 9-(o-Carboxyphenyl)-6-hydroxy-2,4,5,7-tetraiodo-3H-xanthene-3-one disodium salt monohydrate Caswell No. 425AB 3',6-Dihydroxy-2',4',5',7'-tetraiodospiro(isobenzofuran-1(3H),9'(9H)xanthen)-one disodium salt Disodium 9-(O-carboxyphenyl)-6-hydroxy-2,4,5,7-tetraiodo-3H-xanthen-3-one monohydrate

Chemical Function

Dye Solvent

Regulatory Lists

Europe; Personal care - hair coloring children; Europe; Personal care children; Europe; Personal care - specialized bath products - bath salts children; Europe; Personal care - specialized bath products - bubble bath children; Europe; Personal care - dental care - toothpaste children; Europe; Personal care inert_ingredient; non_food_use; Pesticides general_foods pharmaceutical food_additive; Substances Added to Food (formerly EAFUS) (2/2019) Canada; consumer_product; Substances in Products - Canada (4/2014)

Australian Status

AICIS status: listed

Frequently Asked Questions

Is Acid Red 51 (Erythrosine) safe in cosmetics?

Acid Red 51 (Erythrosine) has a safety rating of "MODERATE" in our database. EU status: prohibited. US status: prohibited. 10 toxicological study endpoint(s) are available in our database.

Is Acid Red 51 (Erythrosine) allowed in the EU?

Acid Red 51 (Erythrosine) EU regulatory status: prohibited. This is based on EU Regulation 1223/2009 and its amendments.

What does Acid Red 51 (Erythrosine) do in cosmetics?

Acid Red 51 (Erythrosine) functions as: Cosmetic colorant. It is classified as a cosmetic ingredient in our database. CAS number: 16423-68-0.

What is the NOAEL for Acid Red 51 (Erythrosine)?

The NOAEL (No Observed Adverse Effect Level) for Acid Red 51 (Erythrosine) is =25 mg/kg bw/day based on a reproduction developmental study via oral route in Mouse. A total of 10 study endpoints are available. Source: ToxValDB_ECHA_IUCLID.

Is Acid Red 51 (Erythrosine) used outside cosmetics?

Acid Red 51 (Erythrosine) also appears in industrial chemical safety data. The cross-vertical cards on this page render same-CAS public rows from the matched databases.

Does Acid Red 51 (Erythrosine) have different safety status in cosmetics vs industrial chemicals?

Acid Red 51 (Erythrosine) is prohibited in EU cosmetics but has active industrial GHS classifications (H302, H411, H412, H413).

Compliance Tools

Check Acid Red 51 (Erythrosine) compliance across multiple jurisdictions:

Ingredient Decoder
Paste a full ingredient list for instant analysis
82 Allergen Checker
Check for EU declarable fragrance allergens
Substance Compliance
Check compliance across multiple jurisdictions
MoS Calculator
Calculate Margin of Safety using SCCS methodology
Heavy Metal Limits
Compare limits across jurisdictions

Related Ingredients

Acid Blue 9
Excellent Same category
Colorant, Hair Dyeing
Acid Blue 9 Aluminum Lake
Excellent Same category
Colorant
Anthocyanins
Excellent Same category
Colorant
Beta Vulgaris Extract
Excellent Same category
Skin Conditioning, Colorant (betalain...
Beta Vulgaris Root Extract
Excellent Same category
Skin Conditioning, Colorant (betanin/...
Beta Vulgaris Root Powder
Excellent Same category
Skin conditioning, natural colorant, ...
(20S)-Protopanaxadiol
Moderate Similar safety
(Cnidium Officinale/Coptis Chinensis/Glycyrrhiza Uralensis) Root Extract
Moderate Similar safety
Skin conditioning
(Cryptomeria Japonica/Chamaecyparis Obtusa) Stem Ferment Extract
Moderate Similar safety
Antimicrobial, antioxidant, humectant
(Eclipta Prostrata/Houttuynia Cordata) Leaf Extract
Moderate Similar safety
Skin conditioning
(Lepidium Meyenii/Sarcodon Aspratus) Root Water
Moderate Similar safety
Skin conditioning
(Licorice/Reynoutria Japonica) Root/Stem Extract
Moderate Similar safety
Skin conditioning, antioxidant
ACID RED 51
Moderate Chemical family
Colorant, Hair Dyeing
CI 45430
Moderate Chemical family
Colorant (red iodine-based xanthene dye)
Erythrosin
Poor Chemical family
Colorant
Browse all 30,000+ ingredients A-Z →

Is Acid Red 51 (Erythrosine) in Your Products?

Scan any product label with Piro — our free ingredient scanner. Point your camera at the ingredients list and get instant safety scores for every ingredient.

Try Piro Free →

Analyze Your Full Ingredient List

Paste any INCI list into the Decoder for instant safety analysis, or calculate the Margin of Safety for Acid Red 51 (Erythrosine) in your formulation.

Ingredient Decoder MoS Calculator