Substance profile
Potassium nitrite
Potassium nitrite is white or slightly yellow granules or rods.
01 · Identification
What Potassium nitrite is
Potassium nitrite is white or slightly yellow granules or rods. Its molecular formula is KNO2 and its molecular weight is 85.104 g/mol. It boils at 537 °C, melts at 441 °C.
Under the GHS it carries the signal word Danger.
02 · Identifiers
Potassium nitrite identifiers and molecular data
Potassium nitrite CAS number and EC number
Potassium nitrite molecular formula and molecular weight
03 · GHS classification
Potassium nitrite hazard classification
Harmonised classification under CLP Annex VI. This is the legally binding classification in the EU; other jurisdictions may differ.
Potassium nitrite pictograms and signal word
Potassium nitrite hazard class and category
| Hazard class | Category | From code | Pictogram |
|---|---|---|---|
| Oxidising liquids or Oxidising solids | Category 2 or 3 | H272 | GHS03 |
| Acute toxicity - oral GHS chapter 3.1 | Category 3 | H301 | GHS06 |
| 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 nitrite hazard statements (H-codes)
| Code | Hazard statement |
|---|---|
| H272 | May intensify fire; oxidiser. |
| H301 | Toxic if swallowed. |
| H400 | Very toxic to aquatic life. |
This page lists only the codes assigned to Potassium nitrite. 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 nitrite
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 nitrite 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 nitrite precautionary statements
CLP Annex VI assigns 7 precautionary statements to Potassium nitrite. 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 nitrite 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 нитрит |
| Spanish español | Nitrito de potasio |
| Czech čeština | dusitan draselný |
| Danish dansk | kaliumnitrit |
| German Deutsch | Kaliumnitrit |
| Estonian eesti | kaaliumnitrit |
| Greek ελληνικά | νιτρώδες κάλιο |
| English English | potassium nitrite |
| French français | nitrite de potassium |
| Croatian hrvatski | kalijev nitrit |
| Italian italiano | potassio nitrito |
| Latvian latviešu | kālija nitrīts |
| Lithuanian lietuvių | kalio nitritas |
| Hungarian magyar | kálium-nitrit |
| Maltese Malti | nitrit tal-potassju |
| Dutch Nederlands | kaliumnitriet |
| Polish polski | azotan(III) potasu azotyn potasu |
| Portuguese português | nitrito de potássio |
| Romanian română | azotit de potasiu |
| Slovak slovenčina | dusitan draselný |
| Slovenian slovenščina | kalijev nitrit |
| Finnish suomi | kaliumnitriitti |
| Swedish svenska | kaliumnitrit |
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 nitrite GHS label elements
Everything CLP Annex VI fixes for Potassium nitrite, laid out the way it appears on a label. The greyed lines are the parts only the supplier can fill in.
Danger
Potassium nitrite
- May intensify fire; oxidiser.
- Toxic if swallowed.
- Very toxic to aquatic life.
- Do not eat, drink or smoke when using this product.
- Avoid release to the environment.
- IF SWALLOWED:
- Immediately call a POISON CENTER/doctor/…
- Rinse mouth.
- 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 nitrite in the GHS label constructor →
07 · Health hazards
Potassium nitrite health hazards and exposure limits
Potassium nitrite hazard summary
Strong irritant of the skin and eyes; As an oxidizer, it enhances burning of combustible materials; [CHEMINFO MSDS] Has caused cases of methemoglobinemia when well water was contaminated by fertilizer; [HSDB] See NITRATES and NITRITES.
Source: Haz-Map, Information on Hazardous Chemicals and Occupational Diseases
08 · Physical and chemical properties
Potassium nitrite 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 nitrite boiling point
| Property | Value | Conditions | Source |
|---|---|---|---|
| Boiling point | 537 °C (998.6 °F) | explodes | HSDB |
Potassium nitrite melting point
| Property | Value | Conditions | Source |
|---|---|---|---|
| Melting point | 441 °C (825.8 °F) | HSDB | |
| 440 °C (824 °F) | DOE PAC |
Potassium nitrite density
| Property | Value | Conditions | Source |
|---|---|---|---|
| Density | 1.915 g/cm³ | HSDB | |
| 1.9 g/cm³ | ICSC | ||
| 1.915 g/cm³ | at 25 °C | DOE PAC |
Potassium nitrite solubility
| Property | Value | Conditions | Source |
|---|---|---|---|
| Solubility | SOL IN HOT ALCOHOL; VERY SOL IN LIQUID AMMONIA | HSDB | |
| 306 parts by wt per 100 parts by wt of water at 20 °C | at 20 °C | HSDB | |
| 312 g/100g of water at 25 °C | at 25 °C | HSDB |
Potassium nitrite lower explosive limit (LEL)
| Property | Value | Conditions | Source |
|---|---|---|---|
| Lower explosive limit (LEL) | Prolonged exposure to fire or heat may result in an explosion. | HSDB |
Values compiled from PubChem Laboratory Chemical Safety Summary. Temperatures converted to Fahrenheit for reference.
09 · Fire and explosion
Potassium nitrite 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 nitrite fire potential
Not combustible but enhances combustion of other substances ... /Potassium nitrite/ is a strong oxidant and reacts with combustible and reducing materials causing fire and explosion hazard.
Source: Hazardous Substances Data Bank (HSDB)
Fire and explosion
May explode on heating above 530 °C ... /Potassium nitrite/ is a strong oxidant and reacts with combustible and reducing materials causing fire and explosion hazard.
Source: HSDB
10 · Handling and storage
Potassium nitrite storage and handling
Potassium nitrite safe storage
Fireproof. Provision to contain effluent from fire extinguishing. Separated from combustible substances, reducing agents and acids. Dry. Well closed.
Source: ILO-WHO International Chemical Safety Cards (ICSCs)
Potassium nitrite storage conditions
Keep well closed.
Source: Hazardous Substances Data Bank (HSDB)
Potassium nitrite incompatible materials
Addition of ammonium sulfate to the fused /potassium/ nitrite causes effervescence and ignition.
Source: Hazardous Substances Data Bank (HSDB)
Potassium nitrite reactivity
POTASSIUM NITRITE is an oxidizing agent. Mixtures with phosphorus, tin(II) chloride or other reducing agents may react explosively [Bretherick 1979 p. 108-109]. Contamination by ammonium compounds can initiate spontaneous decomposition. The resulting heat may ignite surrounding combustible material. Reacts with acids to form toxic nitrogen dioxide gas. Mixing with liquid ammonia forms dipotassium nitrite, which is very reactive and easily explosive [Mellor 2, Supp. 3:1566 1963]. Melting together with an ammonium salt leads to a violent explosion [Von Schwartz 1918 p. 299]. A mixture with potassium cyanide may cause an explosion. When a little ammonium sulfate is added to fused potassium nitrite, a vigorous reaction occurs attended by flame [Mellor 2:702. 1946-47].
Source: CAMEO Chemicals
Planning storage for a mix of chemicals? Check Potassium nitrite in the storage compatibility matrix →
11 · Transport
Potassium nitrite 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.
Potassium nitrite under UN 1488 — 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 NITRITE | 5.1 | O2 | II | |
Source: ADR 2025, Table A of Chapter 3.2 · ECE/TRANS/352 Vol. I (UNECE). Class 5.1 is “Oxidizing 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 nitrite | 5.1 | II | |
Source: 49 CFR 172.101 Hazardous Materials Table · eCFR, revision 2026-08-03. Class 5.1 is “Oxidizer” (49 CFR 173.2).
12 · Questions
Potassium nitrite — frequently asked questions
What is the CAS number of Potassium nitrite?
The CAS number of Potassium nitrite is 7758-09-0. Its EC number is 231-832-4.
What is the chemical formula of Potassium nitrite?
The molecular formula of Potassium nitrite is KNO2 and its molecular weight is 85.104 g/mol.
What does a Potassium nitrite label have to show?
Under CLP Annex VI the label for Potassium nitrite carries the pictograms Flame over circle, Skull and crossbones and Environment and the signal word is Danger.
Is Potassium nitrite flammable?
CLP Annex VI assigns Potassium nitrite 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 nitrite a carcinogen?
CLP Annex VI records no harmonised carcinogenicity classification for Potassium nitrite. 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 boiling point of Potassium nitrite?
The boiling point reported for Potassium nitrite is 537 °C (998.6 °F), explodes (HSDB).
What is the melting point of Potassium nitrite?
The melting point reported for Potassium nitrite is 441 °C (825.8 °F) (HSDB).
How should Potassium nitrite be stored?
Keep well closed. (Hazardous Substances Data Bank (HSDB))
Nearby
Substances next to Potassium nitrite
Keep going: substances starting with P, or search the whole database by name, CAS number, pictogram or signal word.