Is Sodium Pyrithione safe in cosmetics?
Sodium Pyrithione has a safety rating of "MODERATE" in our database. EU status: prohibited. US status: permitted. 6 toxicological study endpoint(s) are available in our database.
Sodium Pyrithione
Also known as: 2-Mercaptopyridine N-oxide sodium salt, EINECS 223-296-5, (1-Hydroxy-2-pyridinethione), sodium salt, (1-Hydroxy-2-pyridinethione), sodium salt, tech., 2-Mercaptopyridine oxide sodium salt (+12 more)
INCI: SODIUM PYRITHIONE
Sodium Pyrithione (CAS 3811-73-2) is a cosmetic cosmetic ingredient functioning as Antimicrobial, anti-dandruff agent, preservative. Reported NOAEL =0.5 mg/kg bw/day in Rat (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 and pharmaceutical data.
View industrial chemical safety profile for CAS 3811-73-2 →
Auto-generated CPSR Part A draft with source citations
Cross-Vertical Regulatory Divergence
Sodium Pyrithione is prohibited in EU cosmetics but has active industrial GHS classifications (H302, H312, H332, H311, H331, H315, H317, H319).
Source: Cosmetics: ingredients.eu_status; Chemicals: ghs_classifications.signal_word/hazard_statement_code
Function
Antimicrobial, anti-dandruff agent, preservative
Safety Rating
MODERATE
Chemistry & Identifiers
IUPAC Name
sodium 1-oxidopyridine-2-thione
InChIKey
XNRNJIIJLOFJEK-UHFFFAOYSA-N
Regulatory Status
EU EU Status
prohibited
US US Status
permitted
US Notes
Permitted in the US — available in OTC anti-dandruff products (regulated as drug); not banned by FDA for cosmetic use
For full compliance data across multiple jurisdictions, use the Substance Compliance tool.
Safety Data
Margin of Safety, dermal absorption, and sensitization profile summaries for Sodium Pyrithione.
Calculate MoS for your specific formulation with the MoS Calculator.
Toxicological Studies
6 study endpoints found for Sodium Pyrithione. 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 | =0.5 mg/kg bw/day | oral | Rat | subchronic | ToxValDB_ECHA_IUCLID |
| NOAEL | =0.7 mg/kg bw/day | oral | Rat | reproduction developmental | ToxValDB_ECHA_IUCLID |
| NOAEL | =1.4 mg/kg bw/day | oral | Rat | developmental | ToxValDB_ECHA_IUCLID |
| NOAEL | =1.5 mg/kg bw/day | oral | Rat | developmental | ToxValDB_ECHA_IUCLID |
| NOAEL | =3.5 mg/kg bw/day | oral | Rat | developmental | ToxValDB_ECHA_IUCLID |
| NOAEL | =5 mg/kg bw/day | dermal | Rabbit | developmental | ToxValDB_ECHA_IUCLID |
Sensitization Profile
Contact sensitization data for Sodium Pyrithione based on clinical patch test studies and IFRA standards.
Sensitization Rate
low
Allergen Class
preservative
EU Allergen Listed
no
Patch Test Positive Rate
0.2%
Cross-reactivity Group
none
Reaction Type
contact-dermatitis
Source: IVDK; SCCS
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
Hazard classification: Restricted (Annex XVII)
EU CosIng Annex Listing
European Commission CosIng database Annex references per Regulation (EC) No 1223/2009.
Annex II — Prohibited
Ref: 369
(EC) 2009/1223
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.
SA Saudi SFDA (II - Prohibited)
ASEAN Cosmetic Directive (II)
Ref: 369
BRIN Brazil/India Cosmetics
India: Prohibited (GNRAS)
Additional Jurisdictional Restrictions (4)
| Jurisdiction | Status | Max % | Product Type |
|---|---|---|---|
| IN | banned | - | all cosmetics (zinc pyrithione permitted in Annex C) |
| CA | banned | - | - |
| ASEAN | banned | - | All cosmetic products prohibited |
| KR | prohibited | - | - |
Additional Ingredient Properties
1 property record from structured ingredient metadata.
allergen_detail
{"eu_allergen_listed": "no", "allergen_class": "preservative", "patch_test_frequency_pct": "0.2", "sensitization_rate": "low", "common_reaction_type": "contact-dermatitis", "ifra_restricted": "no", "source": "IVDK; SCCS"}
Function Categories & List Membership
Cosmetic/Chemical Function Categories
Biocide
Regulatory List Membership (2)
EU Banned in Cosmetics
EU CosIng Cosmetics Ingredient Database
Expert Verdict
Expert safety assessment and concern-level summary for Sodium Pyrithione.
Regulatory Flags
preservative
eu_banned_cosmetics
eu_cosing_listed
NOAEL Studies Summary
View details ->Public NOAEL study rows linked to Sodium Pyrithione by CAS number or substance name.
Studies
6
Lowest NOAEL
0.5 mg/kg bw/day
Highest NOAEL
5 mg/kg bw/day
ToxValDB_ECHA_IUCLID
Known Synonyms
2-Mercaptopyridine N-oxide sodium salt
EINECS 223-296-5
(1-Hydroxy-2-pyridinethione), sodium salt
(1-Hydroxy-2-pyridinethione), sodium salt, tech.
2-Mercaptopyridine oxide sodium salt
2-Mercaptopyridine 1-oxide sodium salt
2-Mercaptopyridine-N-oxide sodium salt
NSC 4483
Omadine sodium
1-Oxo-2-pyridinethiol sodium salt
2-Pyridinethiol N-oxide sodium salt
2-Pyridinethiol-1-oxide sodium salt
Sodium 2-mercaptopyridine 1-oxide
Sodium 2-pyridinethiol N-oxide
Sodium 2-pyridinethiol 1-oxide
Sodium 2-pyridinethiolate 1-oxide
Sodium, (2-pyridinylthio)-, N-oxide
Chemical Function
Biocide
Regulatory Lists
CEDI
active_ingredient; Europe; Pesticides
banned; Europe; Personal care
Australian Status
AICIS status: listed
Cross-Vertical Safety Context
Same-CAS public records found in pharmaceutical data.
SOURCE
ChEMBL / DrugCentral / FAERS
DB_PHARMA CAS match
Pharmaceutical Data
Same-CAS rows from the pharmaceutical spoke database.
Compound
PYRITHIONE SODIUM
ChEMBL ID
CHEMBL2364542
Max Phase
-1
Frequently Asked Questions
Is Sodium Pyrithione allowed in the EU?
Sodium Pyrithione EU regulatory status: prohibited. This is based on EU Regulation 1223/2009 and its amendments.
What does Sodium Pyrithione do in cosmetics?
Sodium Pyrithione functions as: Antimicrobial, anti-dandruff agent, preservative. It is classified as a cosmetic ingredient in our database. CAS number: 3811-73-2.
What is the NOAEL for Sodium Pyrithione?
The NOAEL (No Observed Adverse Effect Level) for Sodium Pyrithione is =0.5 mg/kg bw/day based on a subchronic study via oral route in Rat. A total of 6 study endpoints are available. Source: ToxValDB_ECHA_IUCLID.
Is Sodium Pyrithione used outside cosmetics?
Sodium Pyrithione also appears in industrial chemical safety and pharmaceutical data. The cross-vertical cards on this page render same-CAS public rows from the matched databases.
Does Sodium Pyrithione have different safety status in cosmetics vs industrial chemicals?
Sodium Pyrithione is prohibited in EU cosmetics but has active industrial GHS classifications (H302, H312, H332, H311, H331, H315, H317, H319).
Compliance Tools
Check Sodium Pyrithione compliance across multiple jurisdictions:
Ingredient Decoder
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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
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