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

Potassium Fluoride

Potassium Fluoride is white cubic crystals.

CAS 7789-23-3 FK 58.097 g/mol Danger

01 · Identification

What Potassium Fluoride is

Potassium Fluoride is white cubic crystals. Its molecular formula is FK and its molecular weight is 58.097 g/mol. It boils at 1502 °C, melts at 858 °C, is soluble in water.

Under the GHS it carries the signal word Danger.

02 · Identifiers

Potassium Fluoride identifiers and molecular data

Potassium Fluoride CAS number and EC number

CAS number7789-23-3
EC number232-151-5
Index number (CLP Annex VI)009-005-00-2

Potassium Fluoride molecular formula and molecular weight

Molecular formulaFK
Molecular weight58.097 g/mol

03 · GHS classification

Potassium Fluoride hazard classification

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

Potassium Fluoride pictograms and signal word

Signal wordDanger

Potassium Fluoride hazard class and category

GHS hazard classes Potassium Fluoride 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

Potassium Fluoride hazard statements (H-codes)

Hazard statements assigned to Potassium Fluoride
CodeHazard statement
H331 Toxic if inhaled.
H311 Toxic in contact with skin.
H301 Toxic if swallowed.

This page lists only the codes assigned to Potassium Fluoride. 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 Fluoride

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 Fluoride 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 Fluoride precautionary statements

CLP Annex VI assigns 10 precautionary statements to Potassium Fluoride. 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.

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 Fluoride 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 калиев флуорид
Spanish español Fluoruro de potasio
Czech čeština fluorid draselný
Danish dansk kaliumfluorid
German Deutsch Kaliumfluorid
Estonian eesti kaaliumfluoriid
Greek ελληνικά φθοριούχο κάλιο
English English potassium fluoride
French français fluorure de potassium
Croatian hrvatski kalijev fluorid
Italian italiano fluoruro di potassio
Latvian latviešu kālija fluorīds
Lithuanian lietuvių kalio fluoridas
Hungarian magyar kálium-fluorid
Maltese Malti fluworur tal-potassju
Dutch Nederlands kaliumfluoride
Polish polski fluorek potasu
Portuguese português fluoreto de potássio
Romanian română fluorură de potasiu
Slovak slovenčina fluorid draselný
Slovenian slovenščina kalijev fluorid
Finnish suomi kaliumfluoridi
Swedish svenska kaliumfluorid

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 Fluoride GHS label elements

Everything CLP Annex VI fixes for Potassium Fluoride, 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 pictogram

Danger

Potassium Fluoride

  • Toxic if inhaled.
  • Toxic in contact with skin.
  • Toxic if swallowed.
  • 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.
  • 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.
  • Wash with plenty of water/

Supplier name, address and telephone number· Product identifier·Nominal quantity

Need this as an actual label? Open Potassium Fluoride in the GHS label constructor →

07 · Health hazards

Potassium Fluoride health hazards and exposure limits

Potassium Fluoride hazard summary

Toxic by ingestion; A skin, eye, and mucous membrane irritant; Contact with molten substance can cause burns; Reacts with acids to produce toxic hydrogen fluoride gas; [CAMEO]

Source: Haz-Map, Information on Hazardous Chemicals and Occupational Diseases

Potassium Fluoride occupational exposure limits

US occupational exposure limits reported for Potassium Fluoride. PEL is enforceable (OSHA), REL is a recommendation (NIOSH), IDLH is the concentration at which escape becomes impossible without injury.
Limit Value Source
PEL 2.5 [mg/m3], as F Haz-Map, Information on Hazardous Chemicals and Occupational Diseases

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

Potassium Fluoride 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 Fluoride boiling point

Property Value Conditions Source
Boiling point 1502 °C (2735.6 °F) HSDB
1505 °C (2741 °F) at 760 mmHg CAMEO
1502 °C (2735.6 °F) at 760 mmHg DOE PAC

Potassium Fluoride melting point

Property Value Conditions Source
Melting point 858 °C (1576.4 °F) HSDB
19.3 °C (66.7 °F) Tetrahydrate HSDB
857.78 °C (1576 °F) CAMEO

Potassium Fluoride density

Property Value Conditions Source
Density 2.48 g/cm³ HSDB
2.48 g/cm³ at 25 °C DOE PAC

Potassium Fluoride solubility

Property Value Conditions Source
Solubility Soluble in water, hydrogen fluoride; insoluble in alcohol HSDB
102 g/100 g water at 25 °C at 25 °C HSDB
greater than or equal to 100 mg/mL at 66 °F (NTP, 1992) at 18.89 °C CAMEO

Potassium Fluoride vapor pressure

Property Value Conditions Source
Vapor pressure 0.7501 mmHg at 869 °C HSDB
0.75 mmHg at 869 °C DOE PAC

Potassium Fluoride corrosivity

Property Value Conditions Source
Corrosivity Aqueous solution corrodes glass and porcelain HSDB

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

09 · Handling and storage

Potassium Fluoride storage and handling

Potassium Fluoride incompatible materials

Platinum is attacked by bromine trifluoride at 280 °C in presence of potassium fluoride.

Source: Hazardous Substances Data Bank (HSDB)

Potassium Fluoride reactivity

POTASSIUM FLUORIDE reacts with acids to evolve corrosive and toxic hydrogen fluoride. Aqueous solutions corrode glass and consequently are prepared and stored in polyethylene containers. The pure solid may be stored in glass containers. Reacts violently with (Pt + BrF3). [NTP 1992].

Source: CAMEO Chemicals

Planning storage for a mix of chemicals? Check Potassium Fluoride in the storage compatibility matrix →

10 · Transport

Potassium Fluoride 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 Fluoride under UN 1812 — 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 FLUORIDE, SOLID 6.1 T5 III
  • ADR label model 6.1 — Toxic substance
6.1

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)
Potassium fluoride, solid 6.1 III
  • US DOT POISON label (§172.430)
6.1

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 1812 entry — special provisions, packing instructions, quantity limits and the orange plate →

Potassium Fluoride under UN 3422 — 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 FLUORIDE SOLUTION 6.1 T4 III
  • ADR label model 6.1 — Toxic substance
6.1

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)
Potassium fluoride solution 6.1 III
  • US DOT POISON label (§172.430)
6.1

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 3422 entry — special provisions, packing instructions, quantity limits and the orange plate →

11 · Questions

Potassium Fluoride — frequently asked questions

What is the CAS number of Potassium Fluoride?

The CAS number of Potassium Fluoride is 7789-23-3. Its EC number is 232-151-5.

What is the chemical formula of Potassium Fluoride?

The molecular formula of Potassium Fluoride is FK and its molecular weight is 58.097 g/mol.

What does a Potassium Fluoride label have to show?

Under CLP Annex VI the label for Potassium Fluoride carries the pictogram Skull and crossbones and the signal word is Danger.

Is Potassium Fluoride flammable?

CLP Annex VI assigns Potassium Fluoride 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 Fluoride a carcinogen?

CLP Annex VI records no harmonised carcinogenicity classification for Potassium Fluoride. 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 Potassium Fluoride?

The US occupational exposure limit reported for Potassium Fluoride is 2.5 [mg/m3], as F (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 Potassium Fluoride?

The boiling point reported for Potassium Fluoride is 1502 °C (2735.6 °F) (HSDB).

What is the melting point of Potassium Fluoride?

The melting point reported for Potassium Fluoride is 858 °C (1576.4 °F) (HSDB).

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