Substance profile
Chloroform
Chloroform is a highly refractive, nonflammable, heavy, very volatile liquid with a pleasant, etheric, nonirritating odor.
01 · Identification
What Chloroform is
Chloroform is a highly refractive, nonflammable, heavy, very volatile liquid with a pleasant, etheric, nonirritating odor. Its molecular formula is CHCl3 and its molecular weight is 119.37 g/mol. It boils at 61.1 °C, melts at -63.5 °C.
Under the GHS it carries the signal word Danger. It is classed as hazardous Air Pollutants (HAPs).
02 · Identifiers
Chloroform identifiers and molecular data
Chloroform CAS number and EC number
Chloroform molecular formula and molecular weight
Other names for Chloroform
- trichloromethane
- CHCl3
- Formyl Trichloride
- Freon 20
- Hcc 20
- Methane Trichloride
- Methane, Trichloro-
- Methenyl Chloride
- Methenyl Trichloride
- Methyl Trichloride
- R 20
- R 20 (Refrigerant)
- R 20(Refrigerant)
- R-20
03 · GHS classification
Chloroform hazard classification
Harmonised classification under CLP Annex VI. This is the legally binding classification in the EU; other jurisdictions may differ.
Chloroform pictograms and signal word
Chloroform hazard class and category
| Hazard class | Category | From code | Pictogram |
|---|---|---|---|
| Acute toxicity - oral GHS chapter 3.1 | Category 4 | H302 | GHS07 |
| Acute toxicity - inhalation GHS chapter 3.1 | Category 3 | H331 | GHS06 |
| Skin corrosion/irritation GHS chapter 3.2 | Category 2 | H315 | GHS07 |
| Serious eye damage/eye irritation GHS chapter 3.3 | Category 2A | H319 | GHS07 |
| Carcinogenicity GHS chapter 3.6 | Category 2 | H351 | GHS08 |
| Specific target organ toxicity - repeated exposure GHS chapter 3.9 | Category 1 | H372 | GHS08 |
Chloroform hazard statements (H-codes)
| Code | Hazard statement |
|---|---|
| H351 | Suspected of causing cancer <state route of exposure if it is conclusively proven that no other routes of exposure cause the hazard>. |
| H361d | Suspected of damaging the unborn child. |
| H331 | Toxic if inhaled. |
| H302 | Harmful if swallowed. |
| H372 | Causes 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>. |
| H315 | Causes skin irritation. |
| H319 | Causes serious eye irritation. |
This page lists only the codes assigned to Chloroform. 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 Chloroform
Our own Chloroform safety data sheet walks through all sixteen sections of the published data. What it is not is the document an inspector asks for: an SDS is issued for a product by its supplier, so the sheet covering the grade actually standing in your store exists only in that supplier’s version. Collecting those and keeping them current as suppliers revise them is a separate job.
04 · Precautionary statements
Chloroform precautionary statements
CLP Annex VI assigns 20 precautionary statements to Chloroform. 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
Chloroform 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 | хлороформ трихлорометан |
| Spanish español | Cloroformo triclorometano |
| Czech čeština | chloroform trichlormethan |
| Danish dansk | chloroform trichlormethan |
| German Deutsch | Chloroform Trichlormethan |
| Estonian eesti | kloroform triklorometaan |
| Greek ελληνικά | χλωροφόρμιο τριχλωρομεθάνιο |
| English English | chloroform trichloromethane |
| French français | chloroforme trichlorométhane |
| Croatian hrvatski | kloroform triklormetan |
| Italian italiano | cloroformio triclorometano |
| Latvian latviešu | hloroforms trihlormetāns |
| Lithuanian lietuvių | chloroformas trichlormetanas |
| Hungarian magyar | kloroform triklór-metán |
| Maltese Malti | kloroform triklorometan |
| Dutch Nederlands | chloroform trichloormethaan |
| Polish polski | chloroform trichlorometan |
| Portuguese português | clorofórmio triclorometano |
| Romanian română | cloroform triclorometan |
| Slovak slovenčina | chloroform trichlórmetán |
| Slovenian slovenščina | kloroform triklorometan |
| Finnish suomi | kloroformi trikloorimetaani |
| Swedish svenska | kloroform triklormetan |
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
Chloroform GHS label elements
Everything CLP Annex VI fixes for Chloroform, laid out the way it appears on a label. The greyed lines are the parts only the supplier can fill in.
Danger
Chloroform
- Suspected of causing cancer <state route of exposure if it is conclusively proven that no other routes of exposure cause the hazard>.
- Suspected of damaging the unborn child.
- Toxic if inhaled.
- Harmful if swallowed.
- Causes 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>.
- Causes skin irritation.
- Causes serious eye irritation.
- Obtain special instructions before use.
- Do not breathe dust/fume/gas/mist/vapours/spray.
- Wash … thoroughly after handling.
- Do not eat, drink or smoke when using this product.
- Use only outdoors or in a well-ventilated area.
- Wear protective gloves/protective clothing/eye protection/face protection/hearing protection/…
- IF SWALLOWED:
- IF ON SKIN:
- IF INHALED:
- IF IN EYES:
- IF exposed or concerned:
- Immediately call a POISON CENTER/doctor/…
- Call a POISON CENTER/doctor/… if you feel unwell.
- Get medical advice/attention.
- Get medical advice/attention if you feel unwell.
- Rinse mouth.
- If skin irritation occurs:
- If eye irritation persists:
- Remove contact lenses, if present and easy to do. Continue rinsing.
- Wash with plenty of water/…
Supplier name, address and telephone number· Product identifier·Nominal quantity
Need this as an actual label? Open Chloroform in the GHS label constructor →
07 · Health hazards
Chloroform health hazards and exposure limits
Chloroform hazard summary
Chloroform is a colorless liquid with a pleasant, nonirritating odor and a slightly sweet taste. It will burn only when it reaches very high temperatures. In the past, chloroform was used as an inhaled anesthetic during surgery, but it isn't used that way today. Today, chloroform is used to make other chemicals and can also be formed in small amounts when chlorine is added to water. Other names for chloroform aretrichloromethaneandmethyl trichloride.
Source: Agency for Toxic Substances and Disease Registry (ATSDR)
Chloroform carcinogenicity classification
Studied by the US National Toxicology Program: TR-000
Cancer Classification: Group B2 Probable Human Carcinogen
Source: Hazardous Substances Data Bank (HSDB)
Evaluation: There is inadequate evidence in humans for the carcinogenicity of chloroform. There is sufficient evidence in experimental animals for the carcinogenicity of chloroform. Overall evaluation: Chloroform is possibly carcinogenic to humans (Group 2B).
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.
Chloroform occupational exposure limits
| Limit | Value | Source |
|---|---|---|
| PEL | 50 ppm (240 mg/m³) | Occupational Safety and Health Administration (OSHA) |
| PEL | C 50 ppm (240 mg/m3) See Appendix G | The National Institute for Occupational Safety and Health (NIOSH) |
| REL | 2 ppm (9.78 mg/m³) [60 minutes] | Occupational Safety and Health Administration (OSHA) |
| REL | Ca ST 2 ppm (9.78 mg/m3) [60-minute] See Appendix A | The National Institute for Occupational Safety and Health (NIOSH) |
| IDLH | 500 ppm ; A potential occupational carcinogen. (NIOSH, 2024) | CAMEO Chemicals |
| IDLH | 500.0 [ppm] | Haz-Map, Information on Hazardous Chemicals and Occupational Diseases |
| IDLH | NIOSH considers chloroform be a potential occupational carcinogen. | Hazardous Substances Data Bank (HSDB) |
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
Chloroform 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.
Chloroform boiling point
| Property | Value | Conditions | Source |
|---|---|---|---|
| Boiling point | 61.12 °C (142 °F) | HSDB | |
| 61.67 °C (143 °F) | NIOSH | ||
| 61.67 °C (143 °F) | at 760 mmHg | CAMEO |
Chloroform melting point
| Property | Value | Conditions | Source |
|---|---|---|---|
| Melting point | -63.47 °C (-82.2 °F) | HSDB | |
| -63.33 °C (-82 °F) | NIOSH | ||
| -63.5 °C (-82.3 °F) | CAMEO |
Chloroform density
| Property | Value | Conditions | Source |
|---|---|---|---|
| Density | 0.85 g/cm³ | Spirit of chloroform | HSDB |
| 1.484 g/cm³ | at 20 °C | HSDB | |
| 1.4788 g/cm³ | at 25 °C | HSDB |
Chloroform solubility
| Property | Value | Conditions | Source |
|---|---|---|---|
| Solubility | Highly soluble in water | HSDB | |
| In water, 7.95X10+3 mg/L at 25 °C | at 25 °C | HSDB | |
| One mL dissolves in about 200 mL water at 25 °C | at 25 °C | HSDB |
Chloroform vapor pressure
| Property | Value | Conditions | Source |
|---|---|---|---|
| Vapor pressure | 160 mmHg | NIOSH | |
| 159.013 mmHg | at 20 °C | ICSC | |
| 197 mmHg | at 25 °C | HSDB |
Chloroform flash point
| Property | Value | Conditions | Source |
|---|---|---|---|
| Flash point | None (EPA, 1998) | CAMEO |
Chloroform autoignition temperature
| Property | Value | Conditions | Source |
|---|---|---|---|
| Autoignition temperature | Not flammable (USCG, 1999) | CAMEO |
Chloroform lower explosive limit (LEL)
| Property | Value | Conditions | Source |
|---|---|---|---|
| Lower explosive limit (LEL) | Noncombustible Liquid | NIOSH | |
| None (EPA, 1998) | CAMEO |
Chloroform upper explosive limit (UEL)
| Property | Value | Conditions | Source |
|---|---|---|---|
| Upper explosive limit (UEL) | NoneNone (EPA, 1998) | CAMEO |
Chloroform vapor density
| Property | Value | Conditions | Source |
|---|---|---|---|
| Vapor density | 4.12 (air = 1) | HSDB |
Chloroform odor threshold
| Property | Value | Conditions | Source |
|---|---|---|---|
| Odor threshold | 3.30 mg/L (Detection in air; purity not specified) | HSDB | |
| Odor thresholds: low= 250 mg/cu m; high= 1000 mg/cu m. | From table | HSDB | |
| Odor thresholds of 85 ppm and 2.4 ppm have been reported for chloroform in air and water, respectively. | HSDB |
Chloroform critical temperature and pressure
| Property | Value | Conditions | Source |
|---|---|---|---|
| Critical temperature and pressure | 263.33 °C (506 °F) | HSDB |
Chloroform corrosivity
| Property | Value | Conditions | Source |
|---|---|---|---|
| Corrosivity | Liquid chloroform will attack some forms of plastics, rubber, and coatings. | HSDB |
Values compiled from PubChem Laboratory Chemical Safety Summary. Temperatures converted to Fahrenheit for reference.
09 · Fire and explosion
Chloroform 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.
Chloroform fire potential
Not combustible.
Source: Hazardous Substances Data Bank (HSDB)
10 · Handling and storage
Chloroform storage and handling
Chloroform reactive group
CAMEO Chemicals places Chloroform in the reactive group Halogenated Organic Compounds. Compatibility with other chemicals is worked out from the group, not from the individual substance — which is why two substances you have never seen react can still be flagged as a pair that must be separated.
A reactive group is a CAMEO Chemicals (US NOAA) grouping, not a GHS hazard class: it has no code, no category and no legal force. It is what the storage compatibility matrix on this site computes from.
Chloroform safe storage
Store only in original container. Separated from food and feedstuffs and incompatible materials. See Chemical Dangers. Ventilation along the floor. Store in an area without drain or sewer access.
Source: ILO-WHO International Chemical Safety Cards (ICSCs)
Chloroform storage conditions
Keep in tightly closed containers; storage code: LI
Source: Hazardous Substances Data Bank (HSDB)
Chloroform incompatible materials
Mixtures with dinitrogen tetraoxide are explosive when subjected to shock of 25 g TNT equiv or less.
Source: Hazardous Substances Data Bank (HSDB)
Chloroform reactivity
A mixture of acetone and CHLOROFORM in a residue bottle exploded. Since addition of acetone to chloroform in the presence of base will result in a highly exothermic reaction, it is thought that a base was in the bottle. [MCA Case History 1661(1970)]. Powdered aluminum and carbon tetrachloride (also methyl chloride and chloroform or mixtures of these chemicals) exploded when heated (to 153 °C) and by impact, [Chem. Eng. News 32:258(1954); UL Bull. Research 34 (1945), ASESB Pot. Incid. 39(1968)]. An inadequately cooled addition of sodium to a chloroform-methanol mixture (sodium methoxide) caused a violent explosion, [MCA Case History No. 693]. It is incompatible with dinitrogen tetraoxide, fluorine, sodium metal and alcohols, nitromethane, and triisopropylphosphine.
Source: CAMEO Chemicals
Planning storage for a mix of chemicals? Check Chloroform in the storage compatibility matrix →
11 · Transport
Chloroform 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.
Chloroform under UN 1888 — shipping name, class and packing group
Europe · ADR 2025, Table A
| Proper shipping name (3.1.2) | Class | Classification code | PG | Labels (column 5) |
|---|---|---|---|---|
| CHLOROFORM | 6.1 | T1 | III | |
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).
United States · 49 CFR 172.101 Hazardous Materials Table
| Proper shipping name (column 2) | Class or division | PG | Labels (column 6) |
|---|---|---|---|
| Chloroform | 6.1 | III | |
Source: 49 CFR 172.101 Hazardous Materials Table · eCFR, revision 2026-08-03. Class 6.1 is “Poisonous materials” (49 CFR 173.2).
12 · Questions
Chloroform — frequently asked questions
What is the CAS number of Chloroform?
The CAS number of Chloroform is 67-66-3. Its EC number is 200-663-8.
What is the chemical formula of Chloroform?
The molecular formula of Chloroform is CHCl3 and its molecular weight is 119.37 g/mol.
What does a Chloroform label have to show?
Under CLP Annex VI the label for Chloroform carries the pictograms Skull and crossbones and Health hazard and the signal word is Danger.
Is Chloroform flammable?
CLP Annex VI assigns Chloroform 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 None (EPA, 1998) (CAMEO).
Is Chloroform a carcinogen?
CLP Annex VI assigns Chloroform H351 — suspected of causing cancer. That is category 2: the evidence points that way but is not conclusive. IARC places it in Group 2B: possibly carcinogenic to humans.
What is the exposure limit for Chloroform?
The US occupational exposure limit reported for Chloroform is 50 ppm (240 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 Chloroform?
The boiling point reported for Chloroform is 61.12 °C (142 °F) (HSDB).
What is the melting point of Chloroform?
The melting point reported for Chloroform is -63.47 °C (-82.2 °F) (HSDB).
How should Chloroform be stored?
Keep in tightly closed containers; storage code: LI (Hazardous Substances Data Bank (HSDB))
Nearby
Substances next to Chloroform
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