Substance profile
Dichloroacetylene
Dichloroacetylene is a colorless oil with a disagreeable, sweetish odor.
01 · Identification
What Dichloroacetylene is
Dichloroacetylene is a colorless oil with a disagreeable, sweetish odor. Its molecular formula is C2Cl2 and its molecular weight is 94.92 g/mol. It boils at 33 °C, melts at -66 °C.
Under the GHS it carries the signal word Warning. It is classed as flammable agents - 3rd degree.
02 · Identifiers
Dichloroacetylene identifiers and molecular data
Dichloroacetylene CAS number and EC number
Dichloroacetylene molecular formula and molecular weight
03 · GHS classification
Dichloroacetylene hazard classification
Harmonised classification under CLP Annex VI. This is the legally binding classification in the EU; other jurisdictions may differ.
Dichloroacetylene pictograms and signal word
Dichloroacetylene hazard class and category
| Hazard class | Category | From code | Pictogram |
|---|---|---|---|
| Explosives GHS chapter 2.1 | Category Unstable explosive | H200 | GHS01 |
| Carcinogenicity GHS chapter 3.6 | Category 2 | H351 | GHS08 |
| Specific target organ toxicity - repeated exposure GHS chapter 3.9 | Category 2 | H373 | GHS08 |
Dichloroacetylene hazard statements (H-codes)
| Code | Hazard statement |
|---|---|
| H200 | Unstable explosives. |
| H351 | Suspected of causing cancer <state route of exposure if it is conclusively proven that no other routes of exposure cause the hazard>. |
| H373 | May cause damage to organs <or state all organs affected, if known> through prolonged or repeated exposure <state route of exposure if it is conclusively proven that no other routes of exposure cause the hazard>. |
This page lists only the codes assigned to Dichloroacetylene. 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 Dichloroacetylene
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 Dichloroacetylene 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
Dichloroacetylene precautionary statements
CLP Annex VI assigns 8 precautionary statements to Dichloroacetylene. 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.
Prevention
What to do before and during handling so the hazard never happens.
Response
What to do once exposure, spillage or fire has already happened.
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
Dichloroacetylene 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 | дихлороацетилен |
| Spanish español | Dicloroacetileno |
| Czech čeština | dichlorethyn |
| Danish dansk | dichloracetylen |
| German Deutsch | Dichloracetylen |
| Estonian eesti | dikloroatsetüleen |
| Greek ελληνικά | διχλωροακετυλένιο |
| English English | dichloroacetylene |
| French français | dichloroacétylène |
| Croatian hrvatski | dikloracetilen |
| Italian italiano | dicloroacetilene |
| Latvian latviešu | dihloracetilēns |
| Lithuanian lietuvių | dichloracetilenas |
| Hungarian magyar | diklóracetilén |
| Maltese Malti | dikloroaċetilen |
| Dutch Nederlands | dichloroacetyleen |
| Polish polski | dichloroacetylen |
| Portuguese português | dicloroacetileno |
| Romanian română | dicloroacetilenă |
| Slovak slovenčina | dichlóracetylén |
| Slovenian slovenščina | dikloroacetilen |
| Finnish suomi | diklooriasetyleeni |
| Swedish svenska | dikloracetylen |
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
Dichloroacetylene GHS label elements
Everything CLP Annex VI fixes for Dichloroacetylene, laid out the way it appears on a label. The greyed lines are the parts only the supplier can fill in.
Warning
Dichloroacetylene
- Unstable explosives.
- Suspected of causing cancer <state route of exposure if it is conclusively proven that no other routes of exposure cause the hazard>.
- May cause damage to organs <or state all organs affected, if known> through prolonged or repeated exposure <state route of exposure if it is conclusively proven that no other routes of exposure cause the hazard>.
- Obtain special instructions before use.
- Keep away from heat, hot surfaces, sparks, open flames and other ignition sources. No smoking.
- Do not breathe dust/fume/gas/mist/vapours/spray.
- Do not eat, drink or smoke when using this product.
- Wear protective gloves/protective clothing/eye protection/face protection/hearing protection/…
- IF exposed or concerned:
- Get medical advice/attention.
- Get medical advice/attention if you feel unwell.
Supplier name, address and telephone number· Product identifier·Nominal quantity
Need this as an actual label? Open Dichloroacetylene in the GHS label constructor →
07 · Health hazards
Dichloroacetylene health hazards and exposure limits
Dichloroacetylene hazard summary
Dichloroacetylene is formed from the thermal decomposition of trichloroethylene or tetrachloroethane. Dichloroacetylene poisoning causes injury to the kidneys and nervous system. Affected patients may have trigeminal nerve paralysis and reactivation of facial herpes. Most cases were reported when trichloroethylene was used as an anesthetic. [ACGIH]
Source: Haz-Map, Information on Hazardous Chemicals and Occupational Diseases
Dichloroacetylene carcinogenicity classification
Evaluation: No epidemiological data relevant to the carcinogenicity of dichloroacetylene were available. There is limited evidence in experimental animals for the carcinogenicity of dichloroacetylene. Overall evaluation d ichloroacetylene is not classifiable as to its carcinogenicity to humans (Group 3).
Source: Hazardous Substances Data Bank (HSDB)
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.
Dichloroacetylene occupational exposure limits
| Limit | Value | Source |
|---|---|---|
| PEL | 0.1 ppm (0.4 mg/m³) OSHA Construction and Maritime industries only. | Occupational Safety and Health Administration (OSHA) |
| PEL | none See Appendix G | The National Institute for Occupational Safety and Health (NIOSH) |
| REL | 0.1 ppm (0.4 mg/m³) | Occupational Safety and Health Administration (OSHA) |
| REL | Ca C 0.1 ppm (0.4 mg/m3) See Appendix A | The National Institute for Occupational Safety and Health (NIOSH) |
| IDLH | A potential occupational carcinogen. (NIOSH, 2024) | CAMEO Chemicals |
| IDLH | Ca [N.D.] | The National Institute for Occupational Safety and Health (NIOSH) |
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
Dichloroacetylene 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.
Dichloroacetylene boiling point
| Property | Value | Conditions | Source |
|---|---|---|---|
| Boiling point | 33 °C (91.4 °F) | HSDB | |
| 32.22 °C (90 °F) | NIOSH | ||
| 32.22 °C (90 °F) | at 760 mmHg | CAMEO |
Dichloroacetylene melting point
| Property | Value | Conditions | Source |
|---|---|---|---|
| Melting point | -66 °C (-86.8 °F) | ICSC | |
| -65 °C (-85 °F) | DOE PAC | ||
| -65 °C (-85 °F) | range, midpoint shown | HSDB |
Dichloroacetylene density
| Property | Value | Conditions | Source |
|---|---|---|---|
| Density | 1.26 g/cm³ | NIOSH | |
| 1.261 g/cm³ | at 20 °C | HSDB |
Dichloroacetylene solubility
| Property | Value | Conditions | Source |
|---|---|---|---|
| Solubility | Insoluble in water; soluble in ethanol, diethyl ether and acetone | HSDB | |
| Solubility in water: none | ICSC |
Dichloroacetylene vapor pressure
| Property | Value | Conditions | Source |
|---|---|---|---|
| Vapor pressure | 570 mmHg | at 25 °C, Estimated | HSDB |
| 570 mmHg | Haz-Map |
Dichloroacetylene lower explosive limit (LEL)
| Property | Value | Conditions | Source |
|---|---|---|---|
| Lower explosive limit (LEL) | Dichloroacetylene is ...a heat-sensitive explosive gas which ignites in contact with air. | HSDB | |
| Severe explosion hazard. | HSDB | ||
| Combustible Liquid | NIOSH |
Dichloroacetylene vapor density
| Property | Value | Conditions | Source |
|---|---|---|---|
| Vapor density | 3.3 (air = 1) | ICSC |
Values compiled from PubChem Laboratory Chemical Safety Summary. Temperatures converted to Fahrenheit for reference.
09 · Fire and explosion
Dichloroacetylene 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.
Dichloroacetylene fire potential
Spontaneously combustible.
Source: Hazardous Substances Data Bank (HSDB)
10 · Handling and storage
Dichloroacetylene storage and handling
Dichloroacetylene safe storage
Fireproof. Separated from strong acids and oxidants. Cool. Well closed. Keep in a well-ventilated room.
Source: ILO-WHO International Chemical Safety Cards (ICSCs)
Dichloroacetylene incompatible materials
Reacts violently with oxidants and with acids.
Source: Hazardous Substances Data Bank (HSDB)
Dichloroacetylene reactivity
DICHLOROACETYLENE is a reducing agent. Incompatible with oxidizing agents. Can ignite or explode on contact with air or if heated. Can explode if shocked. Burns in the presence of chlorine to form phosgene (Ann. Chem. 640:5(1961)).
Source: CAMEO Chemicals
Planning storage for a mix of chemicals? Check Dichloroacetylene in the storage compatibility matrix →
11 · Questions
Dichloroacetylene — frequently asked questions
What is the CAS number of Dichloroacetylene?
The CAS number of Dichloroacetylene is 7572-29-4.
What is the chemical formula of Dichloroacetylene?
The molecular formula of Dichloroacetylene is C2Cl2 and its molecular weight is 94.92 g/mol.
What does a Dichloroacetylene label have to show?
Under CLP Annex VI the label for Dichloroacetylene carries the pictograms Exploding bomb and Health hazard and the signal word is Warning.
Is Dichloroacetylene flammable?
CLP Annex VI assigns Dichloroacetylene 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.
Is Dichloroacetylene a carcinogen?
CLP Annex VI assigns Dichloroacetylene H351 — suspected of causing cancer. That is category 2: the evidence points that way but is not conclusive. IARC places it in Group 3: not classifiable as to its carcinogenicity to humans.
What is the exposure limit for Dichloroacetylene?
The US occupational exposure limit reported for Dichloroacetylene is 0.1 ppm (0.4 mg/m³) OSHA Construction and Maritime industries only. (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 Dichloroacetylene?
The boiling point reported for Dichloroacetylene is 33 °C (91.4 °F) (HSDB).
What is the melting point of Dichloroacetylene?
The melting point reported for Dichloroacetylene is -66 °C (-86.8 °F) (ICSC).
Nearby
Substances next to Dichloroacetylene
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