Substance profile
Potassium Sulfide
Potassium Sulfide is white cubic crystals or fused plates.
01 · Identification
What Potassium Sulfide is
Potassium Sulfide is white cubic crystals or fused plates. It melts at 912 °C.
Under the GHS it carries the signal word Danger. It is classed as corrosives.
02 · Identifiers
Potassium Sulfide identifiers and molecular data
Potassium Sulfide CAS number and EC number
Potassium Sulfide molecular formula and molecular weight
Other names for Potassium Sulfide
- dipotassium sulphide
- potassium sulphide
03 · GHS classification
Potassium Sulfide hazard classification
Harmonised classification under CLP Annex VI. This is the legally binding classification in the EU; other jurisdictions may differ.
Potassium Sulfide pictograms and signal word
Potassium Sulfide hazard class and category
| Hazard class | Category | From code | Pictogram |
|---|---|---|---|
| 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.
Potassium Sulfide hazard statements (H-codes)
| Code | Hazard statement |
|---|---|
| H314 | Causes severe skin burns and eye damage. |
| H400 | Very toxic to aquatic life. |
Potassium Sulfide supplemental EU statements (EUH)
| Code | Statement |
|---|---|
| EUH031 | Contact with acids liberates toxic gas. |
This page lists only the codes assigned to Potassium Sulfide. 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 Potassium Sulfide
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 Potassium Sulfide 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
Potassium Sulfide precautionary statements
CLP Annex VI assigns 8 precautionary statements to Potassium Sulfide. 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.
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
Potassium Sulfide 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 | дикалиев сулфид калиев сулфид |
| Spanish español | Sulfuro de dipotasio sulfuro de potasio |
| Czech čeština | dikalium-sulfid sulfid draselný |
| Danish dansk | dikaliumsulfid kaliumsulfid |
| German Deutsch | Dikaliumsulfid Kaliumsulfid |
| Estonian eesti | dikaaliumsulfiid kaaliumsulfiid |
| Greek ελληνικά | θειούχο δικάλιο θειούχο κάλιο |
| English English | dipotassium sulphide potassium sulphide |
| French français | sulfure de dipotassium sulfure de potassium |
| Croatian hrvatski | dikalijev sulfid kalijev sulfid |
| Italian italiano | solfuro di dipotassio potassio solfuro |
| Latvian latviešu | dikālija sulfīds kālija sulfīds |
| Lithuanian lietuvių | dikalio sulfidas kalio sulfidas |
| Hungarian magyar | dikálium-szulfid kálium-szulfid |
| Maltese Malti | sulfur tad-dipotassju sulfur tal-potassju |
| Dutch Nederlands | dikaliumsulfide kaliumsulfide |
| Polish polski | siarczek potasu siarczek dipotasu |
| Portuguese português | sulfureto de dipotássio sulfureto de potássio |
| Romanian română | sulfură de dipotasiu sulfură de potasiu |
| Slovak slovenčina | sulfid draselný |
| Slovenian slovenščina | dikalijev sulfid kalijev sulfid |
| Finnish suomi | dikaliumsulfidi kaliumsulfidi |
| Swedish svenska | dikaliumsulfid kaliumsulfid |
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
Potassium Sulfide GHS label elements
Everything CLP Annex VI fixes for Potassium Sulfide, laid out the way it appears on a label. The greyed lines are the parts only the supplier can fill in.
Danger
Potassium Sulfide
- Causes severe skin burns and eye damage.
- Very toxic to aquatic life.
- Contact with acids liberates toxic gas.
- Do not breathe dust/fume/gas/mist/vapours/spray.
- Avoid release to the environment.
- Wear protective gloves/protective clothing/eye protection/face protection/hearing protection/…
- IF SWALLOWED:
- Immediately call a POISON CENTER/doctor/…
- Do NOT induce vomiting.
- Collect spillage.
- Dispose of contents/container to …
Supplier name, address and telephone number· Product identifier·Nominal quantity
Need this as an actual label? Open Potassium Sulfide in the GHS label constructor →
07 · Health hazards
Potassium Sulfide health hazards and exposure limits
Potassium Sulfide hazard summary
May explode on percussion; [Merck Index] May spontaneously ignite; Powder is explosive; [Hawley] A corrosive substance that can cause injury to the skin, eyes, and respiratory tract; Inhalation may cause pulmonary edema; [ICSC] Emergency treatment: Corrosives- alkaline; [HSDB] A strong reducing agent; Pyrophoric; May cause severe skin, eye, and mucous membrane irritation; [CAMEO] Releases hydrogen sulfide on contact with moisture; A corrosive substance that can cause injury to the skin, eyes, and respiratory tract; Inhalation of high concentrations may cause pulmonary edema; [CHEMINFO] A corrosive substance that can cause injury to the skin, eyes, and respiratory tract; [Strem MSDS]
Source: Haz-Map, Information on Hazardous Chemicals and Occupational Diseases
08 · Physical and chemical properties
Potassium Sulfide 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.
Potassium Sulfide melting point
| Property | Value | Conditions | Source |
|---|---|---|---|
| Melting point | 912 °C (1673.6 °F) | HSDB | |
| 840 °C (1544 °F) | ICSC |
Potassium Sulfide density
| Property | Value | Conditions | Source |
|---|---|---|---|
| Density | 1.74 g/cm³ | HSDB | |
| 1.8 g/cm³ | ICSC |
Potassium Sulfide solubility
| Property | Value | Conditions | Source |
|---|---|---|---|
| Solubility | FREELY SOL IN WATER | HSDB | |
| SOL IN ALCOHOL, GLYCERINE; INSOL IN ETHER | HSDB | ||
| Soluble in ethanol, insoluble in ether. | HSDB |
Potassium Sulfide lower explosive limit (LEL)
| Property | Value | Conditions | Source |
|---|---|---|---|
| Lower explosive limit (LEL) | MAY EXPLODE ON PERCUSSION OR RAPID HEATING. | HSDB | |
| MANY SULFIDES REACT VIOLENTLY & EXPLOSIVELY ON CONTACT WITH POWERFUL OXIDIZERS. | SULFIDES | HSDB | |
| Finely divided potassium sulfide may explode in air at room temperature. | HSDB |
Values compiled from PubChem Laboratory Chemical Safety Summary. Temperatures converted to Fahrenheit for reference.
09 · Fire and explosion
Potassium Sulfide 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.
Potassium Sulfide fire potential
Ignites on contact with nitrogen oxide,
Source: Hazardous Substances Data Bank (HSDB)
10 · Handling and storage
Potassium Sulfide storage and handling
Potassium Sulfide safe storage
Fireproof. Separated from strong oxidants and strong acids. Dry.
Source: ILO-WHO International Chemical Safety Cards (ICSCs)
Potassium Sulfide storage conditions
Store in a cool, dry, well-ventilated location. Separate from acids, oxidizing materials, halogens.
Source: Hazardous Substances Data Bank (HSDB)
Potassium Sulfide incompatible materials
Reacts with water to form KOH and KSH.
Source: Hazardous Substances Data Bank (HSDB)
Potassium Sulfide reactivity
POTASSIUM SULFIDE is a reducing agent. So readily oxidized as to be pyrophoric in air [Bretherick 1979 p. 120]. It is incompatible with chloroform and nitrogen oxide.
Source: CAMEO Chemicals
Planning storage for a mix of chemicals? Check Potassium Sulfide in the storage compatibility matrix →
11 · Transport
Potassium Sulfide 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.
Potassium Sulfide under UN 1382 — shipping name, class and packing group
Europe · ADR 2025, Table A
| Proper shipping name (3.1.2) | Class | Classification code | PG | Labels (column 5) |
|---|---|---|---|---|
| POTASSIUM SULPHIDE, ANHYDROUS or POTASSIUM SULPHIDE with less than 30 % water of crystallization | 4.2 | S4 | II | |
Source: ADR 2025, Table A of Chapter 3.2 · ECE/TRANS/352 Vol. I (UNECE). Class 4.2 is “Substances liable to spontaneous combustion” (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) |
|---|---|---|---|
| Potassium sulfide, anhydrous or Potassium sulfide with less than 30 percent water of crystallization | 4.2 | II | |
Source: 49 CFR 172.101 Hazardous Materials Table · eCFR, revision 2026-08-03. Class 4.2 is “Spontaneously combustible material” (49 CFR 173.2).
Potassium Sulfide under UN 1847 — shipping name, class and packing group
Europe · ADR 2025, Table A
| Proper shipping name (3.1.2) | Class | Classification code | PG | Labels (column 5) |
|---|---|---|---|---|
| POTASSIUM SULPHIDE, HYDRATED with not less than 30 % water of crystallization | 8 | C6 | II | |
Source: ADR 2025, Table A of Chapter 3.2 · ECE/TRANS/352 Vol. I (UNECE). Class 8 is “Corrosive 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) |
|---|---|---|---|
| Potassium sulfide, hydrated with not less than 30 percent water of crystallization | 8 | II | |
Source: 49 CFR 172.101 Hazardous Materials Table · eCFR, revision 2026-08-03. Class 8 is “Corrosive material” (49 CFR 173.2).
12 · Questions
Potassium Sulfide — frequently asked questions
What is the CAS number of Potassium Sulfide?
The CAS number of Potassium Sulfide is 1312-73-8. Its EC number is 215-197-0.
What does a Potassium Sulfide label have to show?
Under CLP Annex VI the label for Potassium Sulfide carries the pictograms Corrosion and Environment and the signal word is Danger.
Is Potassium Sulfide flammable?
CLP Annex VI assigns Potassium Sulfide 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 Potassium Sulfide a carcinogen?
CLP Annex VI records no harmonised carcinogenicity classification for Potassium Sulfide. 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 melting point of Potassium Sulfide?
The melting point reported for Potassium Sulfide is 912 °C (1673.6 °F) (HSDB).
How should Potassium Sulfide be stored?
Store in a cool, dry, well-ventilated location. Separate from acids, oxidizing materials, halogens. (Hazardous Substances Data Bank (HSDB))
Nearby
Substances next to Potassium Sulfide
Keep going: substances starting with P, or search the whole database by name, CAS number, pictogram or signal word.