Substance profile
Phosgene
Phosgene is a colorless gas with a suffocating odor; when diluted with air there is an odor reminiscent of moldy.
01 · Identification
What Phosgene is
Phosgene is a colorless gas with a suffocating odor; when diluted with air there is an odor reminiscent of moldy. Its molecular formula is CCl2O and its molecular weight is 98.91 g/mol. It boils at 8.2 °C, melts at -118 °C.
Under the GHS it carries the signal word Danger. It is classed as hazardous Air Pollutants (HAPs).
02 · Identifiers
Phosgene identifiers and molecular data
Phosgene CAS number and EC number
Phosgene molecular formula and molecular weight
Other names for Phosgene
- carbonyl chloride
03 · GHS classification
Phosgene hazard classification
Harmonised classification under CLP Annex VI. This is the legally binding classification in the EU; other jurisdictions may differ.
Phosgene pictograms and signal word
Phosgene hazard class and category
| Hazard class | Category | From code | Pictogram |
|---|---|---|---|
| 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 |
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.
Phosgene hazard statements (H-codes)
| Code | Hazard statement |
|---|---|
| H330 | Fatal if inhaled. |
| H314 | Causes severe skin burns and eye damage. |
This page lists only the codes assigned to Phosgene. 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 Phosgene
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 Phosgene 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
Phosgene precautionary statements
CLP Annex VI assigns 7 precautionary statements to Phosgene. 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
Phosgene 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 | фосген карбонилхлорид |
| Spanish español | Fosgeno cloruro de carbonilo |
| Czech čeština | fosgen chlorid karbonylu |
| Danish dansk | phosgen carbonylchlorid |
| German Deutsch | Phosgen Carbonylchlorid |
| Estonian eesti | fosgeen karbonüülkloriid |
| Greek ελληνικά | φωσγένιο καρβονυλοχλωρίδιοδιχλωροκαρβονύλιο |
| English English | phosgene carbonyl chloride |
| French français | phosgène chlorure de carbonyle |
| Croatian hrvatski | fozgen karbonil-klorid |
| Italian italiano | fosgene carbonile cloruro |
| Latvian latviešu | fosgēns karbonilhlorīds |
| Lithuanian lietuvių | fosgenas karbonilchloridas |
| Hungarian magyar | foszgén karbonil-klorid |
| Maltese Malti | fosġenu klorur tal-karbonil |
| Dutch Nederlands | fosgeen carbonylchloride |
| Polish polski | fosgen chlorek karbonylutlenochlorek węgla |
| Portuguese português | fosgénio cloreto de carbonilo |
| Romanian română | fosgen clorură de carbonil |
| Slovak slovenčina | fosgén dichlorid-oxid uhličtý |
| Slovenian slovenščina | fosgen karbonil klorid |
| Finnish suomi | fosgeeni karbonyylikloridi |
| Swedish svenska | fosgen karbonylklorid |
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
Phosgene GHS label elements
Everything CLP Annex VI fixes for Phosgene, laid out the way it appears on a label. The greyed lines are the parts only the supplier can fill in.
Danger
Phosgene
- Fatal if inhaled.
- Causes severe skin burns and eye damage.
- Do not breathe dust/fume/gas/mist/vapours/spray.
- Use only outdoors or in a well-ventilated area.
- Wear protective gloves/protective clothing/eye protection/face protection/hearing protection/…
- IF SWALLOWED:
- IF INHALED:
- Immediately call a POISON CENTER/doctor/…
- Do NOT induce vomiting.
Supplier name, address and telephone number· Product identifier·Nominal quantity
Need this as an actual label? Open Phosgene in the GHS label constructor →
07 · Health hazards
Phosgene health hazards and exposure limits
Phosgene hazard summary
Phosgene is a colorless nonflammable gas that has the odor of freshly cut hay. It is a manufactured chemical, but small amounts occur naturally from the break down of chlorinated compounds. Phosgene is used in the manufacture of other chemicals such as dyestuffs, isocyanates, polycarbonates and acid chlorides; it is also used in the manufacture of pesticides and pharmaceuticals. Phosgene can also be used to separate ores. Phosgene is a gas at room temperature, but is sometimes stored as a liquid under pressure or refrigeration.
Source: Agency for Toxic Substances and Disease Registry (ATSDR)
Phosgene occupational exposure limits
| Limit | Value | Source |
|---|---|---|
| PEL | 0.1 [ppm] | Haz-Map, Information on Hazardous Chemicals and Occupational Diseases |
| PEL | 0.1 ppm (0.4 mg/m³) | Occupational Safety and Health Administration (OSHA) |
| PEL | TWA 0.1 ppm (0.4 mg/m3) | The National Institute for Occupational Safety and Health (NIOSH) |
| REL | 0.1 ppm (0.4 mg/m³) | Occupational Safety and Health Administration (OSHA) |
| REL | 0.2 ppm (0.8 mg/m³) [15 minutes] | Occupational Safety and Health Administration (OSHA) |
| REL | TWA 0.1 ppm (0.4 mg/m3) C 0.2 ppm (0.8 mg/m3) [15-minute] | The National Institute for Occupational Safety and Health (NIOSH) |
| IDLH | 2 ppm (NIOSH, 2024) | CAMEO Chemicals |
| IDLH | 2.0 [ppm] | Haz-Map, Information on Hazardous Chemicals and Occupational Diseases |
| IDLH | 2 ppm | 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
Phosgene 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.
Phosgene boiling point
| Property | Value | Conditions | Source |
|---|---|---|---|
| Boiling point | 8.2 °C (46.8 °F) | at 760 mmHg | HSDB |
| 8.33 °C (47 °F) | NIOSH | ||
| 8.33 °C (47 °F) | at 760 mmHg | CAMEO |
Phosgene melting point
| Property | Value | Conditions | Source |
|---|---|---|---|
| Melting point | -118 °C (-180.4 °F) | HSDB | |
| -127.78 °C (-198 °F) | NIOSH | ||
| -117.78 °C (-180 °F) | CAMEO |
Phosgene density
| Property | Value | Conditions | Source |
|---|---|---|---|
| Density | 0.52 g/cm³ | HSDB | |
| 1.4 g/cm³ | ICSC | ||
| 1.3719 g/cm³ | at 25 °C | HSDB |
Phosgene solubility
| Property | Value | Conditions | Source |
|---|---|---|---|
| Solubility | Slightly sol in water; freely sol in benzene, toluene, glacial acetic acid, and most liquid hydrocarbons | HSDB | |
| Soluble in benzene, carbon tetrachloride, chloroform, toluene, and acetic acid | HSDB | ||
| Slight | NIOSH |
Phosgene vapor pressure
| Property | Value | Conditions | Source |
|---|---|---|---|
| Vapor pressure | 1216 mmHg | NIOSH | |
| 1215 mmHg | at 20 °C | CAMEO | |
| 1420 mmHg | at 25 °C | HSDB |
Phosgene autoignition temperature
| Property | Value | Conditions | Source |
|---|---|---|---|
| Autoignition temperature | Not flammable (USCG, 1999) | CAMEO |
Phosgene lower explosive limit (LEL)
| Property | Value | Conditions | Source |
|---|---|---|---|
| Lower explosive limit (LEL) | Nonflammable Gas | NIOSH |
Phosgene vapor density
| Property | Value | Conditions | Source |
|---|---|---|---|
| Vapor density | 3.4 (air = 1) | HSDB |
Phosgene critical temperature and pressure
| Property | Value | Conditions | Source |
|---|---|---|---|
| Critical temperature and pressure | 181.85 °C (359.3 °F) | HSDB |
Values compiled from PubChem Laboratory Chemical Safety Summary. Temperatures converted to Fahrenheit for reference.
09 · Fire and explosion
Phosgene 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.
Phosgene fire potential
NONCOMBUSTIBLE
Source: Hazardous Substances Data Bank (HSDB)
Corrosivity
Phosgene used in anhydrous equipment with reagents is not corrosive to ordinary metals. In presence of moisture, corrosive conditions will develop rapidly, in which case monel, tantalum, or glass lined equipment may be used.
Source: HSDB
Odor
Odor cannot be used as a warning for potential exposure. The odor threshold is reported to be between 0.5 and 1.5 parts per million (ppm) ... and tolerance to the pleasant odor of phosgene occurs rapidly.
Source: HSDB
ONE-HALF PART PER MILLION CAN BE RECOGNIZED THROUGH THE SENSE OF SMELL, BY NORMAL PERSONS ACQUAINTED WITH ITS ODOR, BUT OLFACTORY FATIGUE OR ADAPTATION CAN CAUSE A GRADUALLY INCREASING CONCENTRATION TO GO UNNOTICED.
Source: HSDB
The irritant properties of phosgene are not sufficient to give warning of hazardous concn. A trained observer can recognize 0.5 ppm as being "sweet" & at about 1 ppm, the odor becomes typical of the "musty or newmown-hay" smell usually ascribed to phosgene. Workers exposed to phosgene can lose their ability to detect low concn through olfactory fatigue.
Source: HSDB
10 · Handling and storage
Phosgene storage and handling
Phosgene safe storage
Fireproof if in building. Isolated from work area. Separated from incompatible materials. See Chemical Dangers. Cool. Dry. Ventilation along the floor.
Source: ILO-WHO International Chemical Safety Cards (ICSCs)
Phosgene storage conditions
Phosgene must be stored to avoid contact with water, moisture, or steam since violent reactions occur. Store in tightly closed, steel containers in an isolated area away from the work area and separated form all other materials, as well as sunlight. Although phosgene in anhydrous equipment is not corrosive to ordinary metals, in presence of moisture, use monel, tantalum, or glass-lined storage containers. Phosgene should be stored away from heating and cooling ducts. Containers should be frequently inspected for leaks.
Source: Hazardous Substances Data Bank (HSDB)
Phosgene incompatible materials
Violent reaction with strong oxidizers, amines, aluminum. Attacks metals in the presence of water. Attacks plastic, rubber, and coatings.
Source: Hazardous Substances Data Bank (HSDB)
Phosgene reactivity
PHOSGENE is water reactive. Incompatible with strong oxidizing agents, alcohols, amines, alkali. May react violently with aluminum, alkali metals (lithium, potassium, sodium), alcohols (isopropyl alcohol, 2,4-hexadiyn-1,6-diol), sodium azide [Bretherick, 5th ed., 1995, p. 134]. May react vigorously or explosively if mixed with diisopropyl ether or other ethers in the presence of trace amounts of metal salts [J. Haz. Mat., 1981, 4, 291]. Phosgene reacts with phosphate or silicate salts, yielding water-reactive and toxic POCl3 with phosphates (Dunlap, K.L. 2005. Phosgene. In Kirk-Othmer Encyclopedia of Chemical Technology. John Wiley & Sons, Inc.).
Source: CAMEO Chemicals
Planning storage for a mix of chemicals? Check Phosgene in the storage compatibility matrix →
11 · Transport
Phosgene 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.
Phosgene under UN 1076 — shipping name, class and packing group
Europe · ADR 2025, Table A
| Proper shipping name (3.1.2) | Class | Classification code | PG | Labels (column 5) |
|---|---|---|---|---|
| PHOSGENE | 2 | 2TC | — | |
Source: ADR 2025, Table A of Chapter 3.2 · ECE/TRANS/352 Vol. I (UNECE). Class 2 is “Gases” (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) |
|---|---|---|---|
| Phosgene | 2.3 | — | |
Source: 49 CFR 172.101 Hazardous Materials Table · eCFR, revision 2026-08-03. Class 2.3 is “Poisonous gas” (49 CFR 173.2).
12 · Questions
Phosgene — frequently asked questions
What is the CAS number of Phosgene?
The CAS number of Phosgene is 75-44-5. Its EC number is 200-870-3.
What is the chemical formula of Phosgene?
The molecular formula of Phosgene is CCl2O and its molecular weight is 98.91 g/mol.
What does a Phosgene label have to show?
Under CLP Annex VI the label for Phosgene carries the pictograms Gas cylinder, Skull and crossbones and Corrosion and the signal word is Danger.
Is Phosgene flammable?
CLP Annex VI assigns Phosgene 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 Phosgene a carcinogen?
CLP Annex VI records no harmonised carcinogenicity classification for Phosgene. 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 exposure limit for Phosgene?
The US occupational exposure limit reported for Phosgene is 0.1 [ppm] (Haz-Map, Information on Hazardous Chemicals and Occupational Diseases). 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 Phosgene?
The boiling point reported for Phosgene is 8.2 °C (46.8 °F), at 760 mmHg (HSDB).
What is the melting point of Phosgene?
The melting point reported for Phosgene is -118 °C (-180.4 °F) (HSDB).
How should Phosgene be stored?
Phosgene must be stored to avoid contact with water, moisture, or steam since violent reactions occur. Store in tightly closed, steel containers in an isolated area away from the work area and separated form all other materials, as well as sunlight. Although phosgene in anhydrous equipment is not corrosive to ordinary metals, in presence of moisture, use monel, tantalum, or glass-lined storage containers. Phosgene should be stored away from heating and cooling ducts. Containers should be frequently inspected for leaks. (Hazardous Substances Data Bank (HSDB))
Nearby
Substances next to Phosgene
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