Provenance

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

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Substance profile

Chloroacetic Acid

Chloroacetic Acid is monoclinic prisms with a strong vinegar-like odor.

CAS 79-11-8 C2H3ClO2 94.5 g/mol Danger

01 · Identification

What Chloroacetic Acid is

Chloroacetic Acid is monoclinic prisms with a strong vinegar-like odor. Its molecular formula is C2H3ClO2 and its molecular weight is 94.5 g/mol. It boils at 189 °C, melts at 63 °C.

Under the GHS it carries the signal word Danger. It is classed as hazardous Air Pollutants (HAPs).

02 · Identifiers

Chloroacetic Acid identifiers and molecular data

Chloroacetic Acid CAS number and EC number

CAS number79-11-8
EC number201-178-4
Index number (CLP Annex VI)607-003-00-1

Chloroacetic Acid molecular formula and molecular weight

Molecular formulaC2H3ClO2
Molecular weight94.5 g/mol
Chemical class Hazardous Air Pollutants (HAPs)

03 · GHS classification

Chloroacetic Acid hazard classification

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

Chloroacetic Acid pictograms and signal word

Signal wordDanger

Chloroacetic Acid hazard class and category

GHS hazard classes Chloroacetic Acid 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 3 H331 GHS06
Skin corrosion/irritation GHS chapter 3.2 Category 1A or 1B or 1C H314 GHS05
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.

Chloroacetic Acid hazard statements (H-codes)

Hazard statements assigned to Chloroacetic Acid
CodeHazard statement
H331 Toxic 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 Chloroacetic Acid. 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 Chloroacetic Acid

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 Chloroacetic Acid 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

Chloroacetic Acid precautionary statements

CLP Annex VI assigns 14 precautionary statements to Chloroacetic Acid. 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

Chloroacetic Acid 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 хлорооцетна киселина
Spanish español Ácido cloroacético
Czech čeština chloroctová kyselina
Danish dansk chloreddikesyre
German Deutsch Chloressigsäure
Estonian eesti kloroäädikhape
Greek ελληνικά χλωροξικό οξύ
English English chloroacetic acid
French français acide chloroacétique
Croatian hrvatski kloroctena kiselina
Italian italiano acido cloroacetico
Latvian latviešu hloretiķskābe
Lithuanian lietuvių chloracto rūgštis
Hungarian magyar klórecetsav
Maltese Malti aċidu kloroaċetiku
Dutch Nederlands chloorazijnzuur
Polish polski kwas chlorooctowy
Portuguese português ácido cloroacético
Romanian română acid cloroacetic
Slovak slovenčina kyselina chlóroctová
Slovenian slovenščina kloroocetna kislina
Finnish suomi kloorietikkahappo
Swedish svenska klorättiksyra

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

Chloroacetic Acid GHS label elements

Everything CLP Annex VI fixes for Chloroacetic Acid, 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 pictogramGHS05 Corrosion pictogramGHS09 Environment pictogram

Danger

Chloroacetic Acid

  • Toxic if inhaled.
  • Toxic in contact with skin.
  • Toxic if swallowed.
  • Causes severe skin burns and eye damage.
  • Very toxic to aquatic life.
  • 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:
  • Immediately call a POISON CENTER/doctor/
  • 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 Chloroacetic Acid in the GHS label constructor →

07 · Health hazards

Chloroacetic Acid health hazards and exposure limits

Chloroacetic Acid hazard summary

Exposure to chloroacetic acid is most likely to occur in the workplace. Acute (short-term) inhalation or dermal exposure may irritate or cause severe damage to the skin, eyes, respiratory tract, and mucous membranes and cause depression of the central nervous system in humans. No information is available on the chronic (long-term) effects of chloroacetic acid in humans. Damage to the respiratory tract has been observed in rodents chronically exposed to chloroacetic acid by inhalation, orally, and via gavage (experimentally placing the chemical in the stomach). EPA has not classified chloroacetic acid for potential carcinogenicity.

Source: EPA Hazardous Air Pollutants

Chloroacetic Acid carcinogenicity classification

Under the conditions of these 2-year gavage studies, there was no evidence of carcinogenic activity for monochloroacetic acid in male or female F344/N rats given 15 or 30 mg/kg. There was no evidence of carcinogenic activity for monochloroacetic acid in male or female B6C3F1 mice given 50 or 100 mg/kg.

Source: US National Toxicology Program · TR-396: Toxicology and Carcinogenesis Studies of Monochloroacetic Acid (CASRN 79-11-8) in F344/N Rats and B6C3F1 Mice (Gavage Studies) (1992 )

An IARC group and a CLP classification answer different questions. IARC judges whether the evidence for cancer in humans is strong enough; CLP Annex VI is the legally binding EU classification. A substance can carry one and not the other.

08 · Physical and chemical properties

Chloroacetic Acid 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.

Chloroacetic Acid boiling point

Property Value Conditions Source
Boiling point 189.1 °C (372.4 °F) HSDB
188.89 °C (372 °F) at 760 mmHg CAMEO
189 °C (372.2 °F) ICSC

Chloroacetic Acid melting point

Property Value Conditions Source
Melting point 63 °C (145.4 °F) HSDB
62.78 °C (145 °F) CAMEO

Chloroacetic Acid density

Property Value Conditions Source
Density 1.328 g/cm³ CAMEO
1.58 g/cm³ at 20 °C, solid HSDB
1.58 g/cm³ at 20 °C ICSC

Chloroacetic Acid solubility

Property Value Conditions Source
Solubility Soluble in ethanol, diethyl ether, benzene, chloroform; slightly soluble in carbon tetrachloride HSDB
... good solubility in methanol, acetone, diethyl ether, and ethanol, but is only sparingly soluble in hydrocarbons and chlorinated hydrocarbons. HSDB
In water, 8.58X10+5 mg/L at 25 °C at 25 °C HSDB

Chloroacetic Acid vapor pressure

Property Value Conditions Source
Vapor pressure 0.065 mmHg at 25 °C HSDB
1 mmHg at 43 °C CAMEO
7.5 mmHg at 78.4 °C DOE PAC

Chloroacetic Acid flash point

Property Value Conditions Source
Flash point 126.11 °C (259 °F) HSDB
150 °C (302 °F) CAMEO

Chloroacetic Acid autoignition temperature

Property Value Conditions Source
Autoignition temperature 470 °C (878 °F) ICSC
500 °C (932 °F) above this value HSDB

Chloroacetic Acid lower explosive limit (LEL)

Property Value Conditions Source
Lower explosive limit (LEL) 8 % by volume HSDB

Chloroacetic Acid vapor density

Property Value Conditions Source
Vapor density 3.26 (air = 1) HSDB
3.3 (air = 1) ICSC

Chloroacetic Acid odor threshold

Property Value Conditions Source
Odor threshold 0.01 ppm, 0.042 mg/cu m HSDB
Odor Threshold Low: 0.04 [ppm] Haz-Map
Odor Threshold High: 6.14 [ppm] Haz-Map

Chloroacetic Acid critical temperature and pressure

Property Value Conditions Source
Critical temperature and pressure 412.85 °C (775.1 °F) HSDB

Chloroacetic Acid corrosivity

Property Value Conditions Source
Corrosivity ...extremely corrosive and will cause serious chemical burns. HSDB

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

09 · Fire and explosion

Chloroacetic Acid 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.

Chloroacetic Acid fire potential

Combustible liquid when exposed to heat or flame.

Source: Hazardous Substances Data Bank (HSDB)

10 · Handling and storage

Chloroacetic Acid storage and handling

Chloroacetic Acid safe storage

Separated from incompatible materials and food and feedstuffs. See Chemical Dangers. Dry. Store only in original container. Well closed. Ventilation along the floor. Store in an area without drain or sewer access.

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

Chloroacetic Acid storage conditions

Keep container tightly closed in a dry and well-ventilated place.

Source: Hazardous Substances Data Bank (HSDB)

Chloroacetic Acid incompatible materials

Incompatible materials: Strong oxidizing agents, strong bases, strong reducing agents.

Source: Hazardous Substances Data Bank (HSDB)

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

11 · Transport

Chloroacetic Acid UN number and transport classification

Transport classification is a separate system from the GHS classification above. It decides how a package is marked and how a load may be carried; it does not follow from the workplace label, and the workplace label does not follow from it. The entries below are linked by CAS number, never by name.

The same CAS number is shipped under more than one UN number. Which entry applies follows from the form and the concentration of the consignment — read the proper shipping name, not the CAS.

Chloroacetic Acid under UN 1750 — shipping name, class and packing group

Europe · ADR 2025, Table A

Proper shipping name (3.1.2) Class Classification code PG Labels (column 5)
CHLOROACETIC ACID SOLUTION 6.1 TC1 II
  • ADR label model 6.1 — Toxic substance
  • ADR label model 8 — Corrosive substance
6.1, 8

Source: ADR 2025, Table A of Chapter 3.2 · ECE/TRANS/352 Vol. I (UNECE). Class 6.1 is “Toxic substances” (ADR 2.1.1.1).

Proper shipping name (column 2) Class or division PG Labels (column 6)
Chloroacetic acid, solution 6.1 II
  • US DOT POISON label (§172.430)
  • US DOT CORROSIVE label (§172.442)
6.1, 8

Source: 49 CFR 172.101 Hazardous Materials Table · eCFR, revision 2026-08-03. Class 6.1 is “Poisonous materials” (49 CFR 173.2).

Full UN 1750 entry — special provisions, packing instructions, quantity limits and the orange plate →

Chloroacetic Acid under UN 1751 — shipping name, class and packing group

Europe · ADR 2025, Table A

Proper shipping name (3.1.2) Class Classification code PG Labels (column 5)
CHLOROACETIC ACID, SOLID 6.1 TC2 II
  • ADR label model 6.1 — Toxic substance
  • ADR label model 8 — Corrosive substance
6.1, 8

Source: ADR 2025, Table A of Chapter 3.2 · ECE/TRANS/352 Vol. I (UNECE). Class 6.1 is “Toxic substances” (ADR 2.1.1.1).

Proper shipping name (column 2) Class or division PG Labels (column 6)
Chloroacetic acid, solid 6.1 II
  • US DOT POISON label (§172.430)
  • US DOT CORROSIVE label (§172.442)
6.1, 8

Source: 49 CFR 172.101 Hazardous Materials Table · eCFR, revision 2026-08-03. Class 6.1 is “Poisonous materials” (49 CFR 173.2).

Full UN 1751 entry — special provisions, packing instructions, quantity limits and the orange plate →

Chloroacetic Acid under UN 3250 — shipping name, class and packing group

Europe · ADR 2025, Table A

Proper shipping name (3.1.2) Class Classification code PG Labels (column 5)
CHLOROACETIC ACID, MOLTEN 6.1 TC1 II
  • ADR label model 6.1 — Toxic substance
  • ADR label model 8 — Corrosive substance
6.1, 8

Source: ADR 2025, Table A of Chapter 3.2 · ECE/TRANS/352 Vol. I (UNECE). Class 6.1 is “Toxic substances” (ADR 2.1.1.1).

Proper shipping name (column 2) Class or division PG Labels (column 6)
Chloroacetic acid, molten 6.1 II
  • US DOT POISON label (§172.430)
  • US DOT CORROSIVE label (§172.442)
6.1, 8

Source: 49 CFR 172.101 Hazardous Materials Table · eCFR, revision 2026-08-03. Class 6.1 is “Poisonous materials” (49 CFR 173.2).

Full UN 3250 entry — special provisions, packing instructions, quantity limits and the orange plate →

12 · Questions

Chloroacetic Acid — frequently asked questions

What is the CAS number of Chloroacetic Acid?

The CAS number of Chloroacetic Acid is 79-11-8. Its EC number is 201-178-4.

What is the chemical formula of Chloroacetic Acid?

The molecular formula of Chloroacetic Acid is C2H3ClO2 and its molecular weight is 94.5 g/mol.

What does a Chloroacetic Acid label have to show?

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

Is Chloroacetic Acid flammable?

CLP Annex VI assigns Chloroacetic Acid 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 126.11 °C (259 °F) (HSDB).

Is Chloroacetic Acid a carcinogen?

CLP Annex VI records no harmonised carcinogenicity classification for Chloroacetic Acid. Annex VI is a list of agreed classifications, not a list of substances found safe, so this is an absence of a classification rather than a clean bill of health.

What is the boiling point of Chloroacetic Acid?

The boiling point reported for Chloroacetic Acid is 189.1 °C (372.4 °F) (HSDB).

What is the melting point of Chloroacetic Acid?

The melting point reported for Chloroacetic Acid is 63 °C (145.4 °F) (HSDB).

How should Chloroacetic Acid be stored?

Keep container tightly closed in a dry and well-ventilated place. (Hazardous Substances Data Bank (HSDB))

Nearby

Substances next to Chloroacetic Acid

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