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稳定的氯丁二烯（2-氯-1,3-丁二烯） — Chloroprene （stabilized）; （2-chlorobuta-1,3-diene） （CAS No. 126-99-8）

Chloroprene （stabilized）; （2-chlorobuta-1,3-diene） （CAS No. 126-99-8）

The NMPA binding 2021 catalogue prohibits this raw material in cosmetic formulas in China.

All China recordsCompare all marketsOpen official source

Regulatory decision and full conditions

Status
Prohibited
Legal role
Binding rule
Regulatory summary
The NMPA binding 2021 catalogue prohibits this raw material in cosmetic formulas in China.
Conditions and restrictions
Prohibited in cosmetic product formulas. Verify the cited Chinese source identity and any later NMPA amendment before use.

Substance identity

Official source name
稳定的氯丁二烯（2-氯-1,3-丁二烯） — Chloroprene （stabilized）; （2-chlorobuta-1,3-diene） （CAS No. 126-99-8）
CAS
126-99-8
EC
Not supplied in this source row
Identity mapping
standalone:official_nmpa_record
Search this identity across the siteCAS 126-99-8

Cross-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.

9 market datasets
PubChem 2D chemical structure for CAS 126-99-8
CAS 126-99-8PubChem CID 31369

Verified chemistry for CAS 126-99-8

Chloroprene

IUPAC name
2-chlorobuta-1,3-diene
Molecular formula
C4H5Cl
Molecular weight
88.53 g/mol
Exact mass
88.0079779 Da
Monoisotopic mass
88.0079779 Da
XLogP3
2.3
Topological polar surface area
0.0 Ų
Molecular complexity
54.0
Formal charge
0
Hydrogen-bond donors
0
Hydrogen-bond acceptors
0
Rotatable bonds
1
Heavy atoms
5
Covalent units
1

Names and synonyms reported to PubChem

2-Chloro-1,3-butadieneChlorobutadiene2-Chlorobutadiene1,3-Butadiene, 2-chloro-ChloropreenCloroprenebeta-Chloroprene2-Chlor-1,3-butadien
16 more reported names
Chloropren2-Cloro-1,3-butadiene2-Chloor-1,3-butadieen42L93DWV3ANSC-18589CHEBI:39481RefChem:125490204-818-0.beta.-ChloropreneNSC 18589Chloroprene (>96% chloroprene)Chloroprene (99.6% chloroprene)Chloropreen [Dutch]Cloroprene [Italian]2-ChloropreneChloropren [German, Polish]
Open full PubChem recordSafety and hazards at PubChemPubChem annotationsChemical classifications3D structure image
External database identifiers
Advanced structure statistics
Defined atom stereocentres
0
Undefined atom stereocentres
0
Defined bond stereocentres
0
Undefined bond stereocentres
0
3D pharmacophore features
1
3D rings
0
3D hydrophobes
1
3D acceptor features
0
3D donor features
0
3D anionic centres
0
3D cationic centres
0
3D conformers
2
Effective 3D rotors
1.0
Machine-readable structure identifiers
SMILES
C=CC(=C)Cl
InChI
InChI=1S/C4H5Cl/c1-3-4(2)5/h3H,1-2H2
InChIKey
YACLQRRMGMJLJV-UHFFFAOYSA-N

Evidence from additional scientific databases

NIH PubChem PUG-View
Exact identifier match31369

Attributed physical-property, hazard, environmental and use annotations.

  • First Aid: EYES: First check the victim for contact lenses and remove if present. Flush victim's eyes with water or normal saline solution for 20 to 30 minutes while simultaneously calling a hospital or poison control center. Do not put any ointments, oils, or medication in the victim's eyes without specific instructions from a physician. IMMEDIATELY transport the victim after flushing eyes to a hospital even if no symptoms (such as redness or irritation) develop.; SKIN: IMMEDIATELY flood affected skin with water while removing and isolating all contaminated clothing. Gently wash all affected skin areas thoroughly with soap and water. If symptoms such as redness or irritation develop, IMMEDIATELY call a physician and be prepared to transport the victim to a hospital for treatment.; INHALATION: IMMEDIATELY leave the contaminated area; take deep breaths of fresh air. If symptoms (such as wheezing, coughing, shortness of breath, or burning in the mouth, throat, or chest) develop, call a physician and be prepared to transport the victim to a hospital. Provide proper respiratory protection to rescuers entering an unknown atmosphere. Whenever possible, Self-Contained Breathing Apparatus (SCBA) shou Source: CAMEO Chemicals
  • ERG2024, Guide 131P (Chloroprene, stabilized): General First Aid:; · Call 911 or emergency medical service.; · Ensure that medical personnel are aware of the material(s) involved, take precautions to protect themselves and avoid contamination.; · Move victim to fresh air if it can be done safely.; · Administer oxygen if breathing is difficult.; · If victim is not breathing:; -- DO NOT perform mouth-to-mouth resuscitation; the victim may have ingested or inhaled the substance.; -- If equipped and pulse detected, wash face and mouth, then give artificial respiration using a proper respiratory medical device (bag-valve mask, pocket mask equipped with a one-way valve or other device).; -- If no pulse detected or no respiratory medical device available, provide continuous compressions. Conduct a pulse check every two minutes or monitor for any signs of spontaneous respirations.; · Remove and isolate contaminated clothing and shoes.; · For minor skin contact, avoid spreading material on unaffected skin.; · In case of contact with substance, remove immediately by flushing skin or eyes with running water for at least 20 minutes.; · For severe burns, immediate medical attention is required.; · Effects of exposure (inhalation, ingestion, Source: Emergency Response Guidebook (ERG)
  • First Aid: (General first aid procedures); Eye: Irrigate immediately - If this chemical contacts the eyes, immediately wash (irrigate) the eyes with large amounts of water, occasionally lifting the lower and upper lids. Get medical attention immediately.; Skin: Soap wash immediately - If this chemical contacts the skin, immediately wash the contaminated skin with soap and water. If this chemical penetrates the clothing, immediately remove the clothing, wash the skin with soap and water, and get medical attention promptly.; Breathing: Respiratory support; Swallow: Medical attention immediately - If this chemical has been swallowed, get medical attention immediately. Source: The National Institute for Occupational Safety and Health (NIOSH)
  • Signal: Danger Source: Regulation (EC) No 1272/2008 of the European Parliament and of the Council
  • GHS Hazard Statements: H225: Highly Flammable liquid and vapor [Danger Flammable liquids]; H302: Harmful if swallowed [Warning Acute toxicity, oral]; H315: Causes skin irritation [Warning Skin corrosion/irritation]; H319: Causes serious eye irritation [Warning Serious eye damage/eye irritation]; H332: Harmful if inhaled [Warning Acute toxicity, inhalation]; H335: May cause respiratory irritation [Warning Specific target organ toxicity, single exposure; Respiratory tract irritation]; H350: May cause cancer [Danger Carcinogenicity]; H373 **: May causes damage to organs through prolonged or repeated exposure [Warning Specific target organ toxicity, repeated exposure] Source: Regulation (EC) No 1272/2008 of the European Parliament and of the Council
  • Precautionary Statement Codes: P203, P210, P233, P240, P241, P242, P243, P260, P261, P264, P264+P265, P270, P271, P280, P301+P317, P302+P352, P303+P361+P353, P304+P340, P305+P351+P338, P317, P318, P319, P321, P330, P332+P317, P337+P317, P362+P364, P370+P378, P403+P233, P403+P235, P405, and P501 (click each P-code to see the statement) Source: Regulation (EC) No 1272/2008 of the European Parliament and of the Council
  • Signal: Danger Source: European Chemicals Agency (ECHA)
  • GHS Hazard Statements: H225 (100%): Highly Flammable liquid and vapor [Danger Flammable liquids]; H301 (72.1%): Toxic if swallowed [Danger Acute toxicity, oral]; H302+H332 (18.1%): Harmful if swallowed or if inhaled [Warning Acute toxicity, oral; acute toxicity, inhalation]; H302 (27.9%): Harmful if swallowed [Warning Acute toxicity, oral]; H315 (100%): Causes skin irritation [Warning Skin corrosion/irritation]; H319 (100%): Causes serious eye irritation [Warning Serious eye damage/eye irritation]; H332 (100%): Harmful if inhaled [Warning Acute toxicity, inhalation]; H335 (100%): May cause respiratory irritation [Warning Specific target organ toxicity, single exposure; Respiratory tract irritation]; H350 (100%): May cause cancer [Danger Carcinogenicity]; H371 (18.1%): May cause damage to organs [Warning Specific target organ toxicity, single exposure]; H373 (100%): May causes damage to organs through prolonged or repeated exposure [Warning Specific target organ toxicity, repeated exposure]; H411 (89.8%): Toxic to aquatic life with long lasting effects [Hazardous to the aquatic environment, long-term hazard] Source: European Chemicals Agency (ECHA)
  • Precautionary Statement Codes: P203, P210, P233, P240, P241, P242, P243, P260, P261, P264, P264+P265, P270, P271, P273, P280, P301+P316, P301+P317, P302+P352, P303+P361+P353, P304+P340, P305+P351+P338, P308+P316, P317, P318, P319, P321, P330, P332+P317, P337+P317, P362+P364, P370+P378, P391, P403+P233, P403+P235, P405, and P501 (click each P-code to see the statement) Source: European Chemicals Agency (ECHA)
  • ECHA C&L Notifications Summary: Aggregated GHS information provided per 215 reports by companies from 12 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.; Information may vary between notifications depending on impurities, additives, and other factors. The percentage value in parenthesis indicates the notified classification ratio from companies that provide hazard codes. Only hazard codes with percentage values above 10% are shown. For more detailed information, please visit ECHA C&L website. Source: European Chemicals Agency (ECHA)
  • Signal: Danger Source: NITE-CMC
  • GHS Hazard Statements: H225: Highly Flammable liquid and vapor [Danger Flammable liquids]; H301: Toxic if swallowed [Danger Acute toxicity, oral]; H310: Fatal in contact with skin [Danger Acute toxicity, dermal]; H315: Causes skin irritation [Warning Skin corrosion/irritation]; H319: Causes serious eye irritation [Warning Serious eye damage/eye irritation]; H331: Toxic if inhaled [Danger Acute toxicity, inhalation]; H351: Suspected of causing cancer [Warning Carcinogenicity]; H361: Suspected of damaging fertility or the unborn child [Warning Reproductive toxicity]; H370: Causes damage to organs [Danger Specific target organ toxicity, single exposure]; H372: Causes damage to organs through prolonged or repeated exposure [Danger Specific target organ toxicity, repeated exposure] Source: NITE-CMC
  • Precautionary Statement Codes: P203, P210, P233, P240, P241, P242, P243, P260, P261, P262, P264, P264+P265, P270, P271, P280, P301+P316, P302+P352, P303+P361+P353, P304+P340, P305+P351+P338, P308+P316, P316, P318, P319, P321, P330, P332+P317, P337+P317, P361+P364, P362+P364, P370+P378, P403+P233, P403+P235, P405, and P501 (click each P-code to see the statement) Source: NITE-CMC
  • GHS Hazard Statements: H225: Highly Flammable liquid and vapor [Danger Flammable liquids]; H301: Toxic if swallowed [Danger Acute toxicity, oral]; H311: Toxic in contact with skin [Danger Acute toxicity, dermal]; H315: Causes skin irritation [Warning Skin corrosion/irritation]; H319: Causes serious eye irritation [Warning Serious eye damage/eye irritation]; H331: Toxic if inhaled [Danger Acute toxicity, inhalation]; H340: May cause genetic defects [Danger Germ cell mutagenicity]; H350: May cause cancer [Danger Carcinogenicity]; H360: May damage fertility or the unborn child [Danger Reproductive toxicity]; H370: Causes damage to organs [Danger Specific target organ toxicity, single exposure]; H372: Causes damage to organs through prolonged or repeated exposure [Danger Specific target organ toxicity, repeated exposure]; H373: May causes damage to organs through prolonged or repeated exposure [Warning Specific target organ toxicity, repeated exposure] Source: NITE-CMC
  • Signal: Danger Source: Hazardous Chemical Information System (HCIS), Safe Work Australia
  • NFPA Health Rating: 2 - Materials that, under emergency conditions, can cause temporary incapacitation or residual injury. Source: Hazardous Substances Data Bank (HSDB)
  • NFPA Fire Rating: 3 - Liquids and solids that can be ignited under almost all ambient temperature conditions. Materials produce hazardous atmospheres with air under almost all ambient temperatures or, though unaffected by ambient temperatures, are readily ignited under almost all conditions. Source: Hazardous Substances Data Bank (HSDB)
  • NFPA Instability Rating: 0 - Materials that in themselves are normally stable, even under fire conditions. Source: Hazardous Substances Data Bank (HSDB)
  • Environmental Bioconcentration: An estimated BCF of 18 was calculated for 2-chloro-1,3-butadiene(SRC), using an estimated log Kow of 2.53(1) and a regression-derived equation(2). According to a classification scheme(3), this BCF suggests the potential for bioconcentration in aquatic organisms is low (SRC). Source: Hazardous Substances Data Bank (HSDB)
  • Environmental Fate: TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 68(SRC), determined from a structure estimation method(2), indicates that 2-chloro-1,3-butadiene is expected to have high mobility in soil(SRC). Volatilization of 2-chloro-1,3-butadiene from moist soil surfaces is expected to be an important fate process(SRC) given an estimated Henry's Law constant of 0.056 atm-cu m/mole (SRC), using a fragment constant estimation method(3). The potential for volatilization of 2-chloro-1,3-butadiene from dry soil surfaces may exist(SRC) based upon a vapor pressure of 215 mm Hg(4). 2-Chloro-1,3-butadiene will not be susceptible to chemical hydrolysis(SRC). Source: Hazardous Substances Data Bank (HSDB)
  • Environmental Fate: AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 68(SRC), determined from a structure estimation method(2), indicates that 2-chloro-1,3-butadiene is not expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is expected(3) based upon an estimated Henry's Law constant of 0.056 atm-cu m/mole(SRC), developed using a fragment constant estimation method(4). Using this Henry's Law constant and an estimation method(3), volatilization half-lives for a model river and model lake are 3 hours and 4 days, respectively(SRC). According to a classification scheme(5), an estimated BCF of 18(SRC), from an estimated log Kow of 2.53(6) and a regression-derived equation(7), suggests the potential for bioconcentration in aquatic organisms is low. 2-Chloro-1,3-butadiene is not expected to undergo chemical hydrolysis(SRC) because of the lack of hydrolyzable functional groups(3). Source: Hazardous Substances Data Bank (HSDB)
  • Environmental Fate: ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), 2-chloro-1,3-butadiene, which has a vapor pressure of 2.15X10+2 mm Hg at 25 °C, is expected to exist solely as a vapor in the ambient atmosphere. Vapor-phase 2-chloro-1,3-butadiene is degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals, ozone molecules and nitrate radicals(SRC). The half-life for the reaction in air with hydroxyl radicals is estimated to be 18 hours(SRC), calculated from its rate constant of 22X10-12 cu cm/molecule-sec at 25 °C(SRC), determined using a structure estimation method(2). The rate constant for the vapor-phase reaction of 2-chloro-1,3-butadiene with ozone has been estimated as 0.12X10-17 cu cm/molecule-sec at 25 °C(SRC) using a structure estimation method(2). This corresponds to an atmospheric half-life of about 10 days(SRC) at an atmospheric concentration of 7X10+11 ozone molecules per cu cm(3). The gas phase reaction of 2-chloro-1,3-butadiene with nitrate radicals may be an important atmospheric removal process in urban areas at night(4), but the rate of this reaction is not known. Source: Hazardous Substances Data Bank (HSDB)

Mapped by: Existing checksum-valid CAS to unique PubChem CID match. Retrieved: 2026-08-31. Open source record

Scientific classifications and hazard annotations provide context and do not replace the market-specific regulatory decision shown above.

Additional source coverage and match status
SourceResultChecked
NIH PubChem PUG-ViewExact match2026-08-31

A recorded no-match is useful evidence that the source was checked; it is not a claim that the substance does not exist elsewhere.

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
China NMPA banned raw-material catalogues (2021)
Source reference
NMPA 2021 Catalogue of Raw Materials Banned for Cosmetics, entry 402
Source record ID
chemical-402
Source version
NMPA Announcement No. 74 of 2021, effective 2021-05-26
Source language
Chinese with source English/Latin identity
Translation status
Official English translation · English translation
Effective date
2021-05-26
Source updated
2021-05-26
Snapshot checked
2026-08-31 14:13 UTC
Validation method
pdfplumber tables; exact 1,284 + 109 row counts and contiguous source numbering
SHA-256
8848aa3e0c7ac5e74f56fc27927336c4fc2e5bc80137da087c2ca9ba2d2c075e

Registered dataset notes

Dataset coverage
All 1,284 banned raw materials and 109 banned plant/animal raw materials effective from 26 May 2021
Authority note
Binding NMPA catalogues replacing Tables 1 and 2 of the 2015 Technical Specification
Inspect the exact official sourceRegulator guidance

How this record fits the market dataset

1393
current China records
1393
records marked Prohibited
1393
records from this source version
1249
market records with CAS identity

Status distribution

Prohibited: 1393

Condition text is present on 1393 of 1393 current records. An empty condition field is interpreted according to the record type above; it is never converted into an unrestricted-use claim.

China market context

Complete prohibited catalogues plus official-source workflow

Coverage version: NMPA 2021 banned catalogues plus dynamic IECIC List I/List II system current since 2025

All 1,284 banned raw materials and 109 banned plant/animal raw materials, plus the official workflow for the dynamic existing-ingredient inventory, other technical restrictions and new ingredients.

Verification checklist

  1. Search the current NMPA IECIC List I and List II by Chinese name and identity.
  2. Check prohibited/restricted and positive lists in the current Safety and Technical Standards.
  3. Review technical purpose, use history and any monitoring period.
  4. Confirm Chinese labelling, safety assessment and filing/registration duties.

Official market sources

Verification workflow and record completeness

Before using this result in a compliance decision

  1. Confirm that “稳定的氯丁二烯（2-氯-1,3-丁二烯） — Chloroprene （stabilized）; （2-chlorobuta-1,3-diene） （CAS No. 126-99-8）” and every CAS/EC identifier refer to the material in your supplier specification.
  2. Search the current NMPA IECIC List I and List II by Chinese name and identity.
  3. Check prohibited/restricted and positive lists in the current Safety and Technical Standards.
  4. Review technical purpose, use history and any monitoring period.
  5. Confirm Chinese labelling, safety assessment and filing/registration duties.
  6. Document the source version and recheck the regulator before manufacture, notification or market placement.

Fields available in this record

  • Official substance nameAvailable
  • CASAvailable
  • ECNot supplied
  • Separate condition textAvailable
  • Effective dateAvailable
  • Snapshot hash and methodAvailable

Questions this page answers

This official record identifies the substance as prohibited for cosmetic use in the stated market scope. Do not rely on a formulation containing this identity until the cited source, effective date and exact substance match have been verified.

A prohibition entry may contain no separate condition text because the regulatory outcome is the prohibition itself. IECIC listing is not blanket approval; absence may require the new cosmetic ingredient route, and restrictions are checked separately.

The record cites NMPA 2021 Catalogue of Raw Materials Banned for Cosmetics, entry 402, source version NMPA Announcement No. 74 of 2021, effective 2021-05-26. Open the official source.

No. CAS helps resolve identity, but jurisdictions can classify the same substance differently and can apply different product scopes, limits, warnings and transition dates.

Stable citation

稳定的氯丁二烯（2-氯-1,3-丁二烯） — Chloroprene （stabilized）; （2-chlorobuta-1,3-diene） （CAS No. 126-99-8）. NMPA 2021 Catalogue of Raw Materials Banned for Cosmetics, entry 402. China. Source version NMPA Announcement No. 74 of 2021, effective 2021-05-26. CosIng Checker regulatory record: https://cosingchecker.com/regulations/cn/records/12091/

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 China

This official record identifies the substance as prohibited for cosmetic use in the stated market scope.

Do not rely on a formulation containing this identity until the cited source, effective date and exact substance match have been verified.

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: Prohibited
  • Legal role: Binding rule
  • Source version: NMPA Announcement No. 74 of 2021, effective 2021-05-26
  • Effective date: 2021-05-26

What it does not prove

IECIC listing is not blanket approval; absence may require the new cosmetic ingredient route, and restrictions are checked separately.

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 source

FDA 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 source

ILO/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 source

Japan 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 source

NIOSH 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 source

OECD 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 source

US EPA CompTox CTX APIs

API key required for import

DTXSID 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