Provenance

Reference data from EU CLP Annex VI and published regulations — verify against your supplier's SDS before use.

Build a label

Substance profile

Chloroacetaldehyde

Chloroacetaldehyde is a colorless liquid with an acrid, penetrating odor.

CAS 107-20-0 C2H3ClO 78.5 g/mol Danger

01 · Identification

What Chloroacetaldehyde is

Chloroacetaldehyde is a colorless liquid with an acrid, penetrating odor. Its molecular formula is C2H3ClO and its molecular weight is 78.5 g/mol. It boils at 85.5 °C, melts at -16.3 °C, is miscible with water.

Under the GHS it carries the signal word Danger. It is classed as flammable agents - 2nd degree.

02 · Identifiers

Chloroacetaldehyde identifiers and molecular data

Chloroacetaldehyde CAS number and EC number

CAS number107-20-0
EC number203-472-8
Index number (CLP Annex VI)605-025-00-6

Chloroacetaldehyde molecular formula and molecular weight

Molecular formulaC2H3ClO
Molecular weight78.5 g/mol
Chemical class Flammable agents - 2nd degree

03 · GHS classification

Chloroacetaldehyde hazard classification

Harmonised classification under CLP Annex VI. This is the legally binding classification in the EU; other jurisdictions may differ.

Chloroacetaldehyde pictograms and signal word

Signal wordDanger

Chloroacetaldehyde hazard class and category

GHS hazard classes Chloroacetaldehyde falls into
Hazard class Category From code Pictogram
Acute toxicity - oral GHS chapter 3.1 Category 3 H301 GHS06
Acute toxicity - dermal GHS chapter 3.1 Category 3 H311 GHS06
Acute toxicity - inhalation GHS chapter 3.1 Category 1 or 2 H330 GHS06
Skin corrosion/irritation GHS chapter 3.2 Category 1A or 1B or 1C H314 GHS05
Carcinogenicity GHS chapter 3.6 Category 2 H351 GHS08
Hazardous to the aquatic environment - acute GHS chapter 4.1 Category 1 H400 GHS09

Where two values are shown with “or”, the hazard statement is shared by more than one category or by more than one class, and the code alone does not say which. H272, for example, belongs to oxidising liquids and to oxidising solids — the physical state decides. The binding answer for a specific entry is in the CLP Annex VI table itself.

Chloroacetaldehyde hazard statements (H-codes)

Hazard statements assigned to Chloroacetaldehyde
CodeHazard statement
H351 Suspected of causing cancer <state route of exposure if it is conclusively proven that no other routes of exposure cause the hazard>.
H330 Fatal if inhaled.
H311 Toxic in contact with skin.
H301 Toxic if swallowed.
H314 Causes severe skin burns and eye damage.
H400 Very toxic to aquatic life.

This page lists only the codes assigned to Chloroacetaldehyde. The full reference lives on the hazard statements hub, the precautionary statements hub and the GHS pictograms hub.

Safety Data Sheet

Getting an SDS for Chloroacetaldehyde

A Safety Data Sheet is written for a product, not for a substance: the supplier of the grade you actually buy issues it, so two suppliers of Chloroacetaldehyde issue two different sheets. That is why there is no single authoritative SDS for a substance to download — what there is, is the job of collecting the sheets for the products you hold and keeping them current as suppliers revise them.

04 · Precautionary statements

Chloroacetaldehyde precautionary statements

CLP Annex VI assigns 17 precautionary statements to Chloroacetaldehyde. They are grouped the way a label groups them: what to do before handling, what to do when something has already happened, how to store it and how to dispose of it.

Disposal

What has to happen to the contents and the empty container.

Reading the notation. is a blank the supplier fills in — not a truncated sentence.· [square brackets] mark a part printed only when it applies.

05 · Names in the regulation

Chloroacetaldehyde name in 23 EU languages

CLP Annex VI Part 3 is published in every language edition of the regulation, and the identification column is written out in each of them. Nothing below is translated by us: each line is the name as that edition prints it. Under Art. 18(2) the substance name from Annex VI is a lawful product identifier, so this is the wording to put on a label going to that market — and where the cell lists several designations, any one of them qualifies.

Language Name in CLP Annex VI Part 3
Bulgarian български хлороацеталдехид
Spanish español Cloroacetaldehído
Czech čeština chlorethanal
Danish dansk chloracetaldehyd
German Deutsch Chloracetaldehyd
Estonian eesti kloroatseetaldehüüd
Greek ελληνικά χλωροακεταλδεΰδη
English English chloroacetaldehyde
French français chloroacétaldéhyde
Croatian hrvatski kloracetaldehid
Italian italiano cloroacetaldeide
Latvian latviešu hloracetaldehīds
Lithuanian lietuvių chloracetaldehidas
Hungarian magyar klóracetaldehid
Maltese Malti kloroaċetaldeid
Dutch Nederlands chlooraceetaldehyde
Polish polski chloroacetaldehyd
Portuguese português cloroacetaldeído
Romanian română aldehidă cloroacetică
Slovak slovenčina chlóracetaldehyd
Slovenian slovenščina kloroacetaldehid
Finnish suomi klooriasetaldehydi
Swedish svenska kloracetaldehyd

All 23 language editions of Annex VI carry this entry. Irish is the twenty-fourth official EU language and has no line here for a different reason: no consolidated CLP text has ever been published in Irish, so there is no Irish edition of Annex VI to quote a name from. Source: consolidated CLP, CELEX 02008R1272, language editions. © European Union, https://eur-lex.europa.eu — only the electronic Official Journal of the European Union is authentic.

06 · Label elements

Chloroacetaldehyde GHS label elements

Everything CLP Annex VI fixes for Chloroacetaldehyde, laid out the way it appears on a label. The greyed lines are the parts only the supplier can fill in.

GHS06 Skull and crossbones pictogramGHS08 Health hazard pictogramGHS05 Corrosion pictogramGHS09 Environment pictogram

Danger

Chloroacetaldehyde

  • Suspected of causing cancer <state route of exposure if it is conclusively proven that no other routes of exposure cause the hazard>.
  • Fatal if inhaled.
  • Toxic in contact with skin.
  • Toxic if swallowed.
  • Causes severe skin burns and eye damage.
  • Very toxic to aquatic life.
  • Obtain special instructions before use.
  • Do not breathe dust/fume/gas/mist/vapours/spray.
  • Do not eat, drink or smoke when using this product.
  • Use only outdoors or in a well-ventilated area.
  • Avoid release to the environment.
  • Wear protective gloves/protective clothing/eye protection/face protection/hearing protection/
  • IF SWALLOWED:
  • IF ON SKIN:
  • IF INHALED:
  • IF exposed or concerned:
  • Immediately call a POISON CENTER/doctor/
  • Get medical advice/attention.
  • Rinse mouth.
  • Do NOT induce vomiting.
  • Wash with plenty of water/
  • Collect spillage.
  • Dispose of contents/container to

Supplier name, address and telephone number· Product identifier·Nominal quantity

Need this as an actual label? Open Chloroacetaldehyde in the GHS label constructor →

07 · Health hazards

Chloroacetaldehyde health hazards and exposure limits

Chloroacetaldehyde hazard summary

Liquid causes second or third degree burns after short contact; [CHRIS] Exposed subjects complain of mucous membrane irritation, tearing, coughing, and choking; [ACGIH] Can cause pulmonary edema after heavy inhalation exposure; [ICSC]

Source: Haz-Map, Information on Hazardous Chemicals and Occupational Diseases

Chloroacetaldehyde occupational exposure limits

US occupational exposure limits reported for Chloroacetaldehyde. PEL is enforceable (OSHA), REL is a recommendation (NIOSH), IDLH is the concentration at which escape becomes impossible without injury.
Limit Value Source
PEL 1 ppm (3 mg/m³) Occupational Safety and Health Administration (OSHA)
PEL C 1 ppm (3 mg/m3) The National Institute for Occupational Safety and Health (NIOSH)
REL 1 ppm (3 mg/m³) Occupational Safety and Health Administration (OSHA)
REL C 1 ppm (3 mg/m3) The National Institute for Occupational Safety and Health (NIOSH)
IDLH 45 ppm (NIOSH, 2024) CAMEO Chemicals
IDLH 45.0 [ppm] Haz-Map, Information on Hazardous Chemicals and Occupational Diseases
IDLH Excerpts from Documentation for IDLHs: Human data: Volunteers found 45 ppm to be very disagreeable and conjunctival irritation was observed [Dow 1962]. Haz-Map, Information on Hazardous Chemicals and Occupational Diseases

These are United States values. The European Union sets its own indicative and binding limits, and the figure that applies at a given workplace is the one in the local regulation — not the one shown here.

08 · Physical and chemical properties

Chloroacetaldehyde properties

Every value is shown with the conditions it was measured under and the source it came from. Where sources disagree, all values are listed rather than one being picked — the difference is usually a different form of the substance, not an error.

Chloroacetaldehyde boiling point

Property Value Conditions Source
Boiling point 85.5 °C (185.9 °F) HSDB
85.56 °C (186 °F) NIOSH
85 °C (185 °F) at 760 mmHg CAMEO

Chloroacetaldehyde melting point

Property Value Conditions Source
Melting point -16.3 °C (2.7 °F) HSDB
-19.44 °C (-3 °F) NIOSH
-16.11 °C (3 °F) CAMEO

Chloroacetaldehyde density

Property Value Conditions Source
Density 1.19 g/cm³ NIOSH
1.19 g/cm³ at 25 °C HSDB

Chloroacetaldehyde solubility

Property Value Conditions Source
Solubility Miscible in all proportions with water HSDB
Soluble in ether HSDB
Soluble in acetone and methanol HSDB

Chloroacetaldehyde vapor pressure

Property Value Conditions Source
Vapor pressure 100 mmHg NIOSH
99.7582 mmHg at 20 °C ICSC

Chloroacetaldehyde flash point

Property Value Conditions Source
Flash point 87.78 °C (190 °F) HSDB

Chloroacetaldehyde autoignition temperature

Property Value Conditions Source
Autoignition temperature 88 °C (190.4 °F) HSDB

Chloroacetaldehyde lower explosive limit (LEL)

Property Value Conditions Source
Lower explosive limit (LEL) Above 88 °C explosive vapor/air mixtures may be formed. HSDB
Contact with oxidizing materials & acids may cause ... explosions. HSDB
Class IIIA Combustible Liquid: Fl.P. at or above 140 °F and below 200 °F. NIOSH

Chloroacetaldehyde vapor density

Property Value Conditions Source
Vapor density 2.7 (air = 1) CAMEO

Chloroacetaldehyde odor threshold

Property Value Conditions Source
Odor threshold Odor threshold: 3.0 mg/cu m HSDB

Values compiled from PubChem Laboratory Chemical Safety Summary. Temperatures converted to Fahrenheit for reference.

09 · Fire and explosion

Chloroacetaldehyde fire and explosion behaviour

These are descriptions rather than measured values, so they are kept out of the table above and quoted here with the source that reported them.

Chloroacetaldehyde fire potential

MODERATE, WHEN EXPOSED TO HEAT OR FLAME

Source: Hazardous Substances Data Bank (HSDB)

10 · Handling and storage

Chloroacetaldehyde storage and handling

Chloroacetaldehyde safe storage

Separated from strong oxidants, acids, metals and food and feedstuffs.

Source: ILO-WHO International Chemical Safety Cards (ICSCs)

Chloroacetaldehyde storage conditions

Safe Storage: Separated from strong oxidants, acids, metals and food and feedstuffs. /Chloroacetaldehyde (40% Solution)/

Source: Hazardous Substances Data Bank (HSDB)

Chloroacetaldehyde incompatible materials

Oxidizers, acids.

Source: Hazardous Substances Data Bank (HSDB)

Chloroacetaldehyde reactivity

2-CHLOROETHANAL polymerizes on standing. At greater than 50% concentration in water, it forms an insoluble hemihydrate. Sensitive to heat. Reacts with oxidizing agents. Incompatible with acids and water (NTP, 1992). Burns to give poisonous and irritating gases.

Source: CAMEO Chemicals

Planning storage for a mix of chemicals? Check Chloroacetaldehyde in the storage compatibility matrix →

11 · Questions

Chloroacetaldehyde — frequently asked questions

What is the CAS number of Chloroacetaldehyde?

The CAS number of Chloroacetaldehyde is 107-20-0. Its EC number is 203-472-8.

What is the chemical formula of Chloroacetaldehyde?

The molecular formula of Chloroacetaldehyde is C2H3ClO and its molecular weight is 78.5 g/mol.

What does a Chloroacetaldehyde label have to show?

Under CLP Annex VI the label for Chloroacetaldehyde carries the pictograms Skull and crossbones, Health hazard, Corrosion and Environment and the signal word is Danger.

Is Chloroacetaldehyde flammable?

CLP Annex VI assigns Chloroacetaldehyde no flammability hazard class. That is not a statement that it cannot burn: the harmonised list only records the hazards that were assessed for it. The flash point reported for it is 87.78 °C (190 °F) (HSDB).

Is Chloroacetaldehyde a carcinogen?

CLP Annex VI assigns Chloroacetaldehyde H351 — suspected of causing cancer. That is category 2: the evidence points that way but is not conclusive.

What is the exposure limit for Chloroacetaldehyde?

The US occupational exposure limit reported for Chloroacetaldehyde is 1 ppm (3 mg/m³) (Occupational Safety and Health Administration (OSHA)). Limits differ by country: the EU sets its own indicative and binding values, and the figure that applies at a given workplace is the one in the local regulation.

What is the boiling point of Chloroacetaldehyde?

The boiling point reported for Chloroacetaldehyde is 85.5 °C (185.9 °F) (HSDB).

What is the melting point of Chloroacetaldehyde?

The melting point reported for Chloroacetaldehyde is -16.3 °C (2.7 °F) (HSDB).

How should Chloroacetaldehyde be stored?

Safe Storage: Separated from strong oxidants, acids, metals and food and feedstuffs. /Chloroacetaldehyde (40% Solution)/ (Hazardous Substances Data Bank (HSDB))

Get the free GHS / CLP / OSHA deadline calendar

Verified 2026–2029 compliance dates in one PDF — plus alerts when the rules change.