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CAS 1 record

CAS 107-20-0

CAS 107-20-0 matches 1 EU annex record across Annex II–VI of Regulation 1223/2009.

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Chemical identity and properties

PubChem 2D chemical structure for CAS 107-20-0
CAS 107-20-0PubChem CID 33

Chloroacetaldehyde

Chloroacetaldehyde is acetaldehyde substituted at C-2 by chlorine. It is functionally related to an acetaldehyde. — ChEBI

IUPAC name
2-chloroacetaldehyde
Molecular formula
C2H3ClO
Molecular weight
78.50 g/mol
Exact mass
77.9872424 Da
XLogP3
0.3
Topological polar surface area
17.1 Ų
Hydrogen-bond donors
0
Hydrogen-bond acceptors
1
Covalent units
1
Defined stereocentres
0

Also known as

Chloroethanal2-ChloroethanalMonochloroacetaldehydeAcetaldehyde, chloro-Chloroaldehyde2-Chloro-1-ethanalChloroacetaldehyde monomerRCRA waste number P023
16 more reported names
CCRIS 856CF069F5D9CCHEBI:27871RefChem:125356CHLOROACETALDEHYDE (40% AQUEOUS SOLUTION)203-472-8Acetaldehyde, 2-chloro-ChloroacetalaldehydeCH2ClCHOChloroacetaldehyde (~45% in water)alpha-chloroacetaldehydeHSDB 2521EINECS 203-472-8UN2232RCRA waste no. P023BRN 1071226
Open full PubChem recordPubChem annotations3D structure image
External database identifiers

Evidence from additional scientific databases

EMBL-EBI ChEBI
Exact identifier matchCHEBI:27871

chloroacetaldehyde

Acetaldehyde substituted at C-2 by chlorine.

Formula
C2H3ClO
Average mass
78.498 g/mol
Monoisotopic mass
77.98724 Da
Formal charge
0
  • organochlorine compound — is a (CHEBI:36683)
  • acetaldehyde — has functional parent (CHEBI:15343)
  • organochlorine compound — is a (CHEBI:36683)
Additional curated names
chloroacetaldehyde2-Chloro-1-ethanal2-ChloroethanalChloroacetaldehydeChloroaldehydeMonochloroacetaldehyde
Cross-references from this source
  • REGISTRY_NUMBER: 1071226 — Beilstein
  • CAS: 107-20-0 — KEGG COMPOUND
  • CAS: 107-20-0 — ChemIDplus
  • CAS: 107-20-0 — NIST Chemistry WebBook
  • MANUAL_X_REF: c0003 — UM-BBD
  • MANUAL_X_REF: C06754 — KEGG COMPOUND

Mapped by: Exact CAS cross-reference in the ChEBI compound record. Source updated: 2012-10-23. Retrieved: 2026-08-31. Open source record

NIH PubChem PUG-View
Exact identifier match33

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. IMMEDIATELY call a hospital or poison control center even if no symptoms (such as redness or irritation) develop. IMMEDIATELY transport the victim to a hospital for treatment after washing the affected areas.; INHALATION: IMMEDIATELY leave the contaminated area; take deep breaths of fresh air. IMMEDIATELY call a physician and be prepared to transport the victim to a hospital even if no symptoms (such as wheezing, coughing, shortness of breath, or burning in the mouth, throat, or chest) develop. Provide proper respiratory protection to rescuers entering an unknow Source: CAMEO Chemicals
  • ERG2024, Guide 153 (2-Chloroethanal): 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)
  • ERG2024, Guide 153 (Chloroacetaldehyde): 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: Water flush immediately - If this chemical contacts the skin, immediately flush the contaminated skin with water. If this chemical penetrates the clothing, immediately remove the clothing and flush the skin with water. 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: H301: Toxic if swallowed [Danger Acute toxicity, oral]; H311: Toxic in contact with skin [Danger Acute toxicity, dermal]; H314: Causes severe skin burns and eye damage [Danger Skin corrosion/irritation]; H330: Fatal if inhaled [Danger Acute toxicity, inhalation]; H351: Suspected of causing cancer [Warning Carcinogenicity]; H400: Very toxic to aquatic life [Warning Hazardous to the aquatic environment, acute hazard] Source: Regulation (EC) No 1272/2008 of the European Parliament and of the Council
  • Precautionary Statement Codes: P203, P260, P262, P264, P270, P271, P273, P280, P284, P301+P316, P301+P330+P331, P302+P352, P302+P361+P354, P304+P340, P305+P354+P338, P316, P318, P320, P321, P330, P361+P364, P363, P391, P403+P233, 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: H226 (69.1%): Flammable liquid and vapor [Warning Flammable liquids]; H301+H311 (69.1%): Toxic if swallowed or in contact with skin [Danger Acute toxicity, oral; acute toxicity, dermal]; H301 (100%): Toxic if swallowed [Danger Acute toxicity, oral]; H311 (98.2%): Toxic in contact with skin [Danger Acute toxicity, dermal]; H314 (100%): Causes severe skin burns and eye damage [Danger Skin corrosion/irritation]; H330 (100%): Fatal if inhaled [Danger Acute toxicity, inhalation]; H351 (100%): Suspected of causing cancer [Warning Carcinogenicity]; H400 (100%): Very toxic to aquatic life [Warning Hazardous to the aquatic environment, acute hazard] Source: European Chemicals Agency (ECHA)
  • Precautionary Statement Codes: P203, P210, P233, P240, P241, P242, P243, P260, P262, P264, P270, P271, P273, P280, P284, P301+P316, P301+P330+P331, P302+P352, P302+P361+P354, P303+P361+P353, P304+P340, P305+P354+P338, P316, P318, P320, P321, P330, P361+P364, P363, 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 55 reports by companies from 6 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: H227: Combustible liquid [Warning Flammable liquids]; H301: Toxic if swallowed [Danger Acute toxicity, oral]; H310: Fatal in contact with skin [Danger Acute toxicity, dermal]; H314: Causes severe skin burns and eye damage [Danger Skin corrosion/irritation]; H318: Causes serious eye damage [Danger Serious eye damage/eye irritation]; H330: Fatal if inhaled [Danger Acute toxicity, inhalation]; H351: Suspected of causing cancer [Warning Carcinogenicity]; H370: Causes damage to organs [Danger Specific target organ toxicity, single exposure]; H373: May causes damage to organs through prolonged or repeated exposure [Warning Specific target organ toxicity, repeated exposure] Source: NITE-CMC
  • Precautionary Statement Codes: P203, P210, P260, P262, P264, P264+P265, P270, P271, P280, P284, P301+P316, P301+P330+P331, P302+P352, P302+P361+P354, P304+P340, P305+P354+P338, P308+P316, P316, P317, P318, P319, P320, P321, P330, P361+P364, P363, P370+P378, P403, P403+P233, P405, and P501 (click each P-code to see the statement) Source: NITE-CMC
  • GHS Hazard Statements: H227: Combustible liquid [Warning Flammable liquids]; H300: Fatal if swallowed [Danger Acute toxicity, oral]; H310: Fatal in contact with skin [Danger Acute toxicity, dermal]; H314: Causes severe skin burns and eye damage [Danger Skin corrosion/irritation]; H318: Causes serious eye damage [Danger Serious eye damage/eye irritation]; H330: Fatal if inhaled [Danger Acute toxicity, inhalation]; H351: Suspected of causing cancer [Warning Carcinogenicity]; H371: May cause damage to organs [Warning Specific target organ toxicity, single exposure] Source: NITE-CMC
  • Precautionary Statement Codes: P203, P210, P260, P262, P264, P264+P265, P270, P271, P280, P284, P301+P316, P301+P330+P331, P302+P352, P302+P361+P354, P304+P340, P305+P354+P338, P308+P316, P316, P317, P318, P320, P321, P330, P361+P364, P363, P370+P378, P403, P403+P233, P405, and P501 (click each P-code to see the statement) Source: NITE-CMC
  • Environmental Bioconcentration: An estimated BCF of 3 was calculated in fish for chloroacetaldehyde(SRC), using an estimated log Kow of 0.09(1) and a regression-derived equation(1). According to a classification scheme(2), 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 1(SRC), determined from a structure estimation method(2), indicates that chloroacetaldehyde is expected to have very high mobility in soil(SRC). Volatilization of chloroacetaldehyde from moist soil surfaces is expected to be an important fate process(SRC) given an estimated Henry's Law constant of 2.4X10-5 atm-cu m/mole(SRC), using a fragment constant estimation method(3). Chloroacetaldehyde is expected to volatilize from dry soil surfaces(SRC) based upon a vapor pressure of 64.3 mm Hg at 25 °C(4). Biodegradation of chloroacetaldehyde may be important based on degradation studies of 2-chloroethanol which has been shown to degrade via 2-chloroacetaldehyde and 2-chloroacetate to glycollic acid by Pseudomonas CE1r that was isolated from soil(5). Source: Hazardous Substances Data Bank (HSDB)
  • Environmental Fate: AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 1(SRC), determined from a structure estimation method(2), indicates that chloroacetaldehyde 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 2.4X10-5 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 35 hours and 13 days, respectively(SRC). According to a classification scheme(5), an estimated BCF of 3(SRC), from an estimated log Kow of 0.09(2) and a regression-derived equation(2), suggests the potential for bioconcentration in aquatic organisms is low(SRC). Chloroacetaldehyde has a reported hydrolysis rate of 2X10-6 to 5X10-6/hour at 37 °C(6). Biodegradation of chloroacetaldehyde may be important based on degradation studies of 2-chloroethanol which has been shown to degrade via 2-chloroacetaldehyde and 2-chloroacetate to glycollic acid by Pseudomonas CE1r that was isolated from soil(7). 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), chloroacetaldehyde, which has a vapor pressure of 64.3 mm Hg at 25 °C(2), is expected to exist solely as a vapor in the ambient atmosphere. Vapor-phase chloroacetaldehyde is degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals(SRC); the half-life for this reaction in air is estimated to be 4.3 days, calculated from its rate constant of 3.1X10-12 cu cm/molecule-sec(3). Chloroacetaldehyde does not contain chromophores that absorb at wavelengths >290 nm(4) and, therefore, is not expected to be susceptible to direct photolysis by sunlight(SRC). 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
EMBL-EBI ChEBIExact match2026-08-31
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.

Records for CAS 107-20-0

1 total

How CAS 107-20-0 is used on this site

CAS 107-20-0 is the Chemical Abstracts Service identifier used to pin this page to a specific substance. In the current dataset, 1 EU annex record shares this identifier, which helps you cross-check whether the same substance appears under one regulatory context or several.

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A substance identified by CAS 107-20-0 may appear in multiple EU cosmetic regulation annexes when it is subject to different conditions in different contexts. For example, a substance might be restricted under Annex III with specific conditions, and the same CAS might also appear in Annex IV as an approved colorant under separate entry conditions. Each entry must be reviewed individually.

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