Substance profile
Sodium Nitrite
Sodium Nitrite is white, orthorhombic crystals.
01 · Identification
What Sodium Nitrite is
Sodium Nitrite is white, orthorhombic crystals. Its molecular formula is NNaO2 and its molecular weight is 68.995 g/mol. It boils at 115 °C, melts at 271 °C, is slightly soluble in water.
Under the GHS it carries the signal word Danger.
02 · Identifiers
Sodium Nitrite identifiers and molecular data
Sodium Nitrite CAS number and EC number
Sodium Nitrite molecular formula and molecular weight
03 · GHS classification
Sodium Nitrite hazard classification
Harmonised classification under CLP Annex VI. This is the legally binding classification in the EU; other jurisdictions may differ.
Sodium Nitrite pictograms and signal word
Sodium 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.
Sodium 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 Sodium 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 Sodium 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 Sodium 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
Sodium Nitrite precautionary statements
CLP Annex VI assigns 7 precautionary statements to Sodium 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
Sodium 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 | натриев нитрит |
| Spanish español | Nitrito de sodio |
| Czech čeština | dusitan sodný |
| Danish dansk | natriumnitrit |
| German Deutsch | Natriumnitrit |
| Estonian eesti | naatriumnitrit |
| Greek ελληνικά | νιτρώδες νάτριο |
| English English | sodium nitrite |
| French français | nitrite de sodium |
| Croatian hrvatski | natrijev nitrit |
| Italian italiano | sodio nitrito |
| Latvian latviešu | nātrija nitrīts |
| Lithuanian lietuvių | natrio nitritas |
| Hungarian magyar | nátrium-nitrit |
| Maltese Malti | nitritu tas-sodju |
| Dutch Nederlands | natriumnitriet |
| Polish polski | azotan(III) sodu azotyn sodu |
| Portuguese português | nitrito de sódio |
| Romanian română | azotit de sodiu |
| Slovak slovenčina | dusitan sodný |
| Slovenian slovenščina | natrijev nitrit |
| Finnish suomi | natriumnitriitti |
| Swedish svenska | natriumnitrit |
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
Sodium Nitrite GHS label elements
Everything CLP Annex VI fixes for Sodium Nitrite, laid out the way it appears on a label. The greyed lines are the parts only the supplier can fill in.
Danger
Sodium 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 Sodium Nitrite in the GHS label constructor →
07 · Health hazards
Sodium Nitrite health hazards and exposure limits
Sodium Nitrite hazard summary
Emergency treatment: Nitrites; [HSDB] A strong oxidant that reacts with combustible and reducing substances posing fire and explosion hazard; An eye irritant; Can induce methemoglobinemia; [ICSC] A strong oxidizing agent; May explode on prolonged exposure to heat; An eye irritant; Can induce methemoglobinemia; [CAMEO] May cause moderate eye irritation, based on animal studies; [CHEMINFO] See NITRATES and NITRITES.
Source: Haz-Map, Information on Hazardous Chemicals and Occupational Diseases
Sodium Nitrite carcinogenicity classification
Under the conditions of this 2-year drinking water study, there was no evidence of carcinogenic activity of sodium nitrite in male or female F344/N rats exposed to 750, 1,500, or 3,000 ppm. There was no evidence of carcinogenic activity of sodium nitrite in male B6C3F1 mice exposed to 750, 1,500, or 3,000 ppm. There was equivocal evidence of carcinogenic activity of sodium nitrite in female B6C3F1 mice based on the positive trend in the incidences of squamous cell papilloma or carcinoma (combined) of the forestomach.
Source: US National Toxicology Program · TR-495: Toxicology and Carcinogenesis Studies of Sodium Nitrite (CASRN 7632-00-0) in F344/N Rats and B6C3F1 Mice (Drinking Water Studies) (2001 )
There is limited evidence in humans for the carcinogenicity of nitrite in food. Nitrite in food is associated with an increased incidence of stomach cancer. ...There is sufficient evidence in experimental animals for the carcinogenicity of nitrite in combination with amines or amides. There is limited evidence in experimental animals for the carcinogenicity of nitrite per se. Overall evaluation: Ingested nitrate or nitrite under conditions that result in endogenous nitrosation is probably carcinogenic to humans (Group 2A).
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.
08 · Physical and chemical properties
Sodium 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.
Sodium Nitrite boiling point
| Property | Value | Conditions | Source |
|---|---|---|---|
| Boiling point | 115 °C (239 °F) | at 760 mmHg | CAMEO |
| 320 °C (608 °F) | decomposes | CAMEO |
Sodium Nitrite melting point
| Property | Value | Conditions | Source |
|---|---|---|---|
| Melting point | 271 °C (519.8 °F) | HSDB | |
| 271.11 °C (520 °F) | CAMEO | ||
| -1.11 °C (30 °F) | CAMEO |
Sodium Nitrite density
| Property | Value | Conditions | Source |
|---|---|---|---|
| Density | 2.17 g/cm³ | HSDB | |
| 2.2 g/cm³ | ICSC | ||
| 2.17 g/cm³ | at 20 °C | CAMEO |
Sodium Nitrite solubility
| Property | Value | Conditions | Source |
|---|---|---|---|
| Solubility | Sol in water; moderately sol in methanol; sparingly soluble in diethyl ether | HSDB | |
| Slightly soluble in ethanol | HSDB | ||
| Sol in 1.5 parts cold, 0.6 parts boiling water. | HSDB |
Sodium Nitrite autoignition temperature
| Property | Value | Conditions | Source |
|---|---|---|---|
| Autoignition temperature | 537.78 °C (1000 °F) | CAMEO |
Sodium Nitrite lower explosive limit (LEL)
| Property | Value | Conditions | Source |
|---|---|---|---|
| Lower explosive limit (LEL) | Explodes when heated to over 1,000 °C ... | HSDB | |
| Shock may explode them ... | Nitrites | HSDB |
Values compiled from PubChem Laboratory Chemical Safety Summary. Temperatures converted to Fahrenheit for reference.
09 · Fire and explosion
Sodium 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.
Sodium Nitrite fire potential
Not combustible but enhances combustion of other substances ... /Sodium 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 ... /Sodium nitrite/ is a strong oxidant and reacts with combustible and reducing materials causing fire and explosion hazard.
Source: HSDB
10 · Handling and storage
Sodium Nitrite storage and handling
Sodium Nitrite safe storage
Separated from combustible substances, reducing agents and acids. Dry. Well closed.
Source: ILO-WHO International Chemical Safety Cards (ICSCs)
Sodium Nitrite storage conditions
Separated from combustible and reducing substances, acids. Dry. Well closed.
Source: Hazardous Substances Data Bank (HSDB)
Sodium Nitrite incompatible materials
... /They/ can react vigorously with reducing materials. /Nitrites/
Source: Hazardous Substances Data Bank (HSDB)
Sodium Nitrite reactivity
SODIUM NITRITE SOLUTION is an oxidizing agent. Reacts with reducing agents to generate heat and products that may be gaseous (causing pressurization inside closed containers). The products may themselves be capable of further reactions (such as combustion). Dissolution in water reduces but does not nullify the oxidizing power of nitrites. Reacts with acids to form toxic nitrogen dioxide gas. Mixtures with phosphorus, tin(II) chloride or other reducing agents may react explosively [Bretherick 1979 p. 108-109]. When a mixture with sodium thiosulfate was heated to dryness, a violent explosion occurred [Mellor 10:501 1946-47]. May react with organic amines to give carcinogens (nitrosamines).
Source: CAMEO Chemicals
Planning storage for a mix of chemicals? Check Sodium Nitrite in the storage compatibility matrix →
11 · Transport
Sodium 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.
Sodium Nitrite under UN 1500 — shipping name, class and packing group
Europe · ADR 2025, Table A
| Proper shipping name (3.1.2) | Class | Classification code | PG | Labels (column 5) |
|---|---|---|---|---|
| SODIUM NITRITE | 5.1 | OT2 | III | |
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) |
|---|---|---|---|
| Sodium nitrite | 5.1 | III | |
Source: 49 CFR 172.101 Hazardous Materials Table · eCFR, revision 2026-08-03. Class 5.1 is “Oxidizer” (49 CFR 173.2).
12 · Questions
Sodium Nitrite — frequently asked questions
What is the CAS number of Sodium Nitrite?
The CAS number of Sodium Nitrite is 7632-00-0. Its EC number is 231-555-9.
What is the chemical formula of Sodium Nitrite?
The molecular formula of Sodium Nitrite is NNaO2 and its molecular weight is 68.995 g/mol.
What does a Sodium Nitrite label have to show?
Under CLP Annex VI the label for Sodium Nitrite carries the pictograms Flame over circle, Skull and crossbones and Environment and the signal word is Danger.
Is Sodium Nitrite flammable?
CLP Annex VI assigns Sodium 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 Sodium Nitrite a carcinogen?
CLP Annex VI records no harmonised carcinogenicity classification for Sodium 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 Sodium Nitrite?
The boiling point reported for Sodium Nitrite is 115 °C (239 °F), at 760 mmHg (CAMEO).
What is the melting point of Sodium Nitrite?
The melting point reported for Sodium Nitrite is 271 °C (519.8 °F) (HSDB).
How should Sodium Nitrite be stored?
Separated from combustible and reducing substances, acids. Dry. Well closed. (Hazardous Substances Data Bank (HSDB))
Nearby
Substances next to Sodium Nitrite
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