시스테인, 아세틸시스테인 및 그 염류
Listed by the Korean MFDS as a cosmetic ingredient requiring conditions of use.
Regulatory decision and full conditions
- Status
- Restricted
- Legal role
- Binding rule
- Regulatory summary
- Listed by the Korean MFDS as a cosmetic ingredient requiring conditions of use.
- Conditions and restrictions
- 퍼머넌트웨이 브용 제품에 시스테인으로 서 3.0~7.5% (다만, 가온2욕식 퍼머넌트웨 이브용 제품의 경우에는 시스테인으로 서 1.5～5.5%, 안정제로서 치오글라이콜 릭애씨드 1.0%를 배합할 수 있으며, 첨가하는 치오글라이콜 릭애씨드의 양을 최대한 1.0%로 했을 때 주성분인 시스테인의 양은 6.5%를 초과할 수 없다) · L-시스테인DL-시스테인시스테인에이치씨엘아세틸시스테인
Substance identity
- Official source name
- 시스테인, 아세틸시스테인 및 그 염류
- CAS
- 52-90-4; 3374-22-9; 52-89-1; 616-91-1
- EC
- 200-157-7
- Identity mapping
- cas_number
- Linked ingredient
- CYSTEINE HCL
Linked CosIng identity data
Names and aliases
CosIng description: Cysteine hydrochloride
Recorded cosmetic function: ANTIOXIDANT, HAIR CONDITIONING, HAIR WAVING OR STRAIGHTENING, REDUCING
Function pages:ANTIOXIDANT, HAIR CONDITIONING, HAIR WAVING OR STRAIGHTENING, REDUCING
View the complete ingredient profileCross-market snapshot for this identity
Exact linked records currently present in this site. An absent market means no imported exact match, not permission to use the substance.
South Korea
Current record1 linked record · 1 with specific conditions
Open supporting recordVerified chemistry for CAS 3374-22-9
DL-cysteine
Cysteine is a sulfur-containing amino acid that is propanoic acid with an amino group at position 2 and a sulfanyl group at position 3. It has a role as a fundamental metabolite. It is a polar amino acid, a sulfur-containing amino acid and an alpha-amino acid. It contains a sulfanylmethyl group. It is a conjugate base of a cysteinium. It is a conjugate acid of a cysteinate(1-). It is a tautomer of a cysteine zwitterion. — ChEBI
- IUPAC name
- 2-amino-3-sulfanylpropanoic acid
- Molecular formula
- C3H7NO2S
- Molecular weight
- 121.16 g/mol
- Exact mass
- 121.01974964 Da
- Monoisotopic mass
- 121.01974964 Da
- XLogP3
- -2.5
- Topological polar surface area
- 64.3 Ų
- Molecular complexity
- 75.0
- Formal charge
- 0
- Hydrogen-bond donors
- 3
- Hydrogen-bond acceptors
- 4
- Rotatable bonds
- 2
- Heavy atoms
- 7
- Covalent units
- 1
Names and synonyms reported to PubChem
16 more reported names
External database identifiers
- ChEBI:CHEBI:15356
- ChEMBL:CHEMBL54943
- EPA DTXSID:DTXSID5046988
- PubMed:23024785
- PubMed:22867025
- PubMed:22813754
- PubMed:22769850
- PubMed:22572786
- PubMed:22539321
- PubMed:22533155
- PubMed:22524145
- PubMed:22523489
- PubMed:22427952
- PubMed:22405311
- PubMed:22365687
Advanced structure statistics
- Defined atom stereocentres
- 0
- Undefined atom stereocentres
- 1
- Defined bond stereocentres
- 0
- Undefined bond stereocentres
- 0
- 3D pharmacophore features
- 5
- 3D rings
- 0
- 3D hydrophobes
- 0
- 3D acceptor features
- 2
- 3D donor features
- 1
- 3D anionic centres
- 1
- 3D cationic centres
- 1
- 3D conformers
- 10
- Effective 3D rotors
- 2.0
Machine-readable structure identifiers
- SMILES
C(C(C(=O)O)N)S- InChI
InChI=1S/C3H7NO2S/c4-2(1-7)3(5)6/h2,7H,1,4H2,(H,5,6)- InChIKey
XUJNEKJLAYXESH-UHFFFAOYSA-N
Retrieved from NIH PubChem on 2026-08-31 by checksum-valid CAS matching. Chemical properties do not replace the regulatory decision on this page.
Verified chemistry for CAS 52-89-1
Cysteine Hydrochloride
- IUPAC name
- (2R)-2-amino-3-sulfanylpropanoic acid;hydrochloride
- Molecular formula
- C3H8ClNO2S
- Molecular weight
- 157.62 g/mol
- Exact mass
- 156.9964274 Da
- Monoisotopic mass
- 156.9964274 Da
- Topological polar surface area
- 64.3 Ų
- Molecular complexity
- 75.0
- Formal charge
- 0
- Hydrogen-bond donors
- 4
- Hydrogen-bond acceptors
- 4
- Rotatable bonds
- 2
- Heavy atoms
- 8
- Covalent units
- 2
Names and synonyms reported to PubChem
16 more reported names
External database identifiers
- ChEBI:CHEBI:91247
- ChEMBL:CHEMBL1200630
- EPA DTXSID:DTXSID0020367
- PubMed:9107
Advanced structure statistics
- Defined atom stereocentres
- 1
- Undefined atom stereocentres
- 0
- Defined bond stereocentres
- 0
- Undefined bond stereocentres
- 0
- 3D conformers
- 0
Machine-readable structure identifiers
- SMILES
C([C@@H](C(=O)O)N)S.Cl- InChI
InChI=1S/C3H7NO2S.ClH/c4-2(1-7)3(5)6;/h2,7H,1,4H2,(H,5,6);1H/t2-;/m0./s1- InChIKey
IFQSXNOEEPCSLW-DKWTVANSSA-N
Retrieved from NIH PubChem on 2026-08-31 by checksum-valid CAS matching. Chemical properties do not replace the regulatory decision on this page.
Verified chemistry for CAS 52-90-4
L-(+)-Cysteine
- IUPAC name
- (2R)-2-amino-3-sulfanylpropanoic acid
- Molecular formula
- C3H7NO2S
- Molecular weight
- 121.16 g/mol
- Exact mass
- 121.01974964 Da
- Monoisotopic mass
- 121.01974964 Da
- XLogP3
- -2.5
- Topological polar surface area
- 64.3 Ų
- Molecular complexity
- 75.0
- Formal charge
- 0
- Hydrogen-bond donors
- 3
- Hydrogen-bond acceptors
- 4
- Rotatable bonds
- 2
- Heavy atoms
- 7
- Covalent units
- 1
Names and synonyms reported to PubChem
16 more reported names
External database identifiers
Advanced structure statistics
- Defined atom stereocentres
- 1
- Undefined atom stereocentres
- 0
- Defined bond stereocentres
- 0
- Undefined bond stereocentres
- 0
- 3D pharmacophore features
- 5
- 3D rings
- 0
- 3D hydrophobes
- 0
- 3D acceptor features
- 2
- 3D donor features
- 1
- 3D anionic centres
- 1
- 3D cationic centres
- 1
- 3D conformers
- 9
- Effective 3D rotors
- 2.0
Machine-readable structure identifiers
- SMILES
C([C@@H](C(=O)O)N)S- InChI
InChI=1S/C3H7NO2S/c4-2(1-7)3(5)6/h2,7H,1,4H2,(H,5,6)/t2-/m0/s1- InChIKey
XUJNEKJLAYXESH-REOHCLBHSA-N
Retrieved from NIH PubChem on 2026-08-31 by checksum-valid CAS matching. Chemical properties do not replace the regulatory decision on this page.
Verified chemistry for CAS 616-91-1
N-Acetyl-L-Cysteine
- IUPAC name
- (2R)-2-acetamido-3-sulfanylpropanoic acid
- Molecular formula
- C5H9NO3S
- Molecular weight
- 163.20 g/mol
- Exact mass
- 163.03031432 Da
- Monoisotopic mass
- 163.03031432 Da
- XLogP3
- 0.4
- Topological polar surface area
- 67.4 Ų
- Molecular complexity
- 148.0
- Formal charge
- 0
- Hydrogen-bond donors
- 3
- Hydrogen-bond acceptors
- 4
- Rotatable bonds
- 3
- Heavy atoms
- 10
- Covalent units
- 1
Names and synonyms reported to PubChem
16 more reported names
External database identifiers
Advanced structure statistics
- Defined atom stereocentres
- 1
- Undefined atom stereocentres
- 0
- Defined bond stereocentres
- 0
- Undefined bond stereocentres
- 0
- 3D pharmacophore features
- 5
- 3D rings
- 0
- 3D hydrophobes
- 0
- 3D acceptor features
- 3
- 3D donor features
- 1
- 3D anionic centres
- 1
- 3D cationic centres
- 0
- 3D conformers
- 10
- Effective 3D rotors
- 4.0
Machine-readable structure identifiers
- SMILES
CC(=O)N[C@@H](CS)C(=O)O- InChI
InChI=1S/C5H9NO3S/c1-3(7)6-4(2-10)5(8)9/h4,10H,2H2,1H3,(H,6,7)(H,8,9)/t4-/m0/s1- InChIKey
PWKSKIMOESPYIA-BYPYZUCNSA-N
Retrieved from NIH PubChem on 2026-08-31 by checksum-valid CAS matching. Chemical properties do not replace the regulatory decision on this page.
Official source and provenance
- Registered source
- South Korea MFDS cosmetic ingredient data
- Source reference
- 화장품 안전기준 등에 관한 규정, 별표 2, record 2-359
- Source record ID
2-359- Source version
- 2026-19
- Source language
- Korean
- Translation status
- No English translation
- Effective date
- 2026-03-18
- Source updated
- 2026-03-18
- Snapshot checked
- 2026-08-30 04:33 UTC
- Validation method
- MFDS JSON appendices 1–2 parse; 1077 prohibited, 243 restricted
- SHA-256
056de35b843a5e31f709073f9e79d5e6e18f7c9164eb537bb099b185a37ef7d8
Registered dataset notes
- Dataset coverage
- Ingredient identity and separate restriction/regulation data endpoints
- Authority note
- Korean source is canonical; English materials alone are not complete enough for certification
How this record fits the market dataset
Status distribution
Condition text is present on 638 of 1320 current records. An empty condition field is interpreted according to the record type above; it is never converted into an unrestricted-use claim.
South Korea market context
Complete current appendix dataset
Coverage version: MFDS Notice 2026-19, effective 18 March 2026
All rows in official Appendix 1 (prohibited) and Appendix 2 (restricted) of the Safety Standards for Cosmetics.
Verification checklist
- Match the Korean canonical substance name and identifiers.
- Review all Appendix 1 and 2 matches and conditions.
- Check functional-cosmetic and positive-list requirements where applicable.
- Confirm current MFDS notice, responsible seller and label obligations.
Official market sources
- South Korea MFDS cosmetic ingredient dataKorean source is canonical; English materials alone are not complete enough for certification
Verification workflow and record completeness
Before using this result in a compliance decision
- Confirm that “시스테인, 아세틸시스테인 및 그 염류” and every CAS/EC identifier refer to the material in your supplier specification.
- Match the Korean canonical substance name and identifiers.
- Review all Appendix 1 and 2 matches and conditions.
- Check functional-cosmetic and positive-list requirements where applicable.
- Confirm current MFDS notice, responsible seller and label obligations.
- Document the source version and recheck the regulator before manufacture, notification or market placement.
Fields available in this record
- Official substance nameAvailable
- CASAvailable
- ECAvailable
- Separate condition textAvailable
- Effective dateAvailable
- Snapshot hash and methodAvailable
Questions this page answers
Stable citation
시스테인, 아세틸시스테인 및 그 염류. 화장품 안전기준 등에 관한 규정, 별표 2, record 2-359. South Korea. Source version 2026-19. CosIng Checker regulatory record: https://cosingchecker.com/regulations/kr/records/2098/
Cite the regulator as the legal authority. This page is a structured evidence index and verification aid, not a substitute for the official text or professional legal assessment.
Interpretation and limits for South Korea
This substance is not unrestricted: cosmetic use is subject to the conditions in the cited official record.
Check product type, body area, concentration, purity and warning requirements before deciding whether a formulation is compliant.
How to interpret the legal role
The cited row forms part of a binding rule or legally incorporated list for this market.
Evidence on this page
- Recorded outcome: Restricted
- Legal role: Binding rule
- Source version: 2026-19
- Effective date: 2026-03-18
What it does not prove
Korean source wording is canonical and other positive lists/notices may still apply to the formulation.
Further authoritative substance research
These sources can add identity, safety, exposure or hazard context. A link is not evidence that the database contains this exact substance, and none of these sources overrides the market decision above.
Cosmetic Ingredient Review safety assessments
Expert Panel conclusions, assessed ingredient groups, use conditions, dates and report documents
Independent expert review considered by FDA; not a government approval or binding market rule
Research this identity at the sourceFDA Global Substance Registration System
UNII identifiers, preferred names, substance types, codes and public substance relationships
Identity registry only; UNII availability does not imply FDA review or approval
Research this identity at the sourceILO/WHO International Chemical Safety Cards
Hazards, symptoms, first aid, storage, incompatibilities and physical properties for covered chemicals
International occupational chemical-safety reference; not cosmetic-use approval
Research this identity at the sourceJapan NITE-CHRIP
Chemical identity, Japanese and foreign legal lists, GHS hazards and exposure-related information
Chemical-management evidence; cosmetic status remains governed by the applicable MHLW standard and market rules
Research this identity at the sourceNIOSH Pocket Guide to Chemical Hazards
REL, PEL, IDLH, properties, exposure routes, symptoms, target organs, first aid and measurement methods for covered workplace chemicals
US occupational-health guidance and limits; not a cosmetic ingredient decision
Research this identity at the sourceOECD eChemPortal
Gateway to authority-owned physical-property, fate, ecotoxicity, toxicity, exposure and GHS records
Discovery gateway; each linked authority remains responsible for its data
Research this identity at the sourceUS EPA CompTox CTX APIs
API key required for importDTXSID identity, experimental and predicted properties, toxicity, bioactivity, exposure and environmental data
Scientific and computational evidence; predictions must remain labelled and do not determine cosmetic legality
Research this identity at the source