Substance profile
Magnesium powder (pyrophoric)
Magnesium powder (pyrophoric) is a silvery-white metal with a none odor.
01 · Identification
What Magnesium powder (pyrophoric) is
Magnesium powder (pyrophoric) is a silvery-white metal with a none odor. It boils at 1100 °C, melts at 651 °C, is practically insoluble in water.
Under the GHS it carries the signal word Danger. It is classed as reactive agents - 1st degree.
02 · Identifiers
Magnesium powder (pyrophoric) identifiers and molecular data
Magnesium powder (pyrophoric) CAS number and EC number
Magnesium powder (pyrophoric) molecular formula and molecular weight
03 · GHS classification
Magnesium powder (pyrophoric) hazard classification
Harmonised classification under CLP Annex VI. This is the legally binding classification in the EU; other jurisdictions may differ.
Magnesium powder (pyrophoric) pictograms and signal word
Magnesium powder (pyrophoric) hazard class and category
| Hazard class | Category | From code | Pictogram |
|---|---|---|---|
| Pyrophoric liquids or Pyrophoric solids | Category 1 | H250 | GHS02 |
| In contact with water emits flammable gases GHS chapter 2.12 | Category 1 | H260 | GHS02 |
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.
Magnesium powder (pyrophoric) hazard statements (H-codes)
| Code | Hazard statement |
|---|---|
| H250 | Catches fire spontaneously if exposed to air. |
| H260 | In contact with water releases flammable gases which may ignite spontaneously. |
This page lists only the codes assigned to Magnesium powder…. 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 Magnesium powder…
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 Magnesium powder… 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
Magnesium powder (pyrophoric) precautionary statements
CLP Annex VI assigns 6 precautionary statements to Magnesium powder…. 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.
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
Magnesium powder (pyrophoric) 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 | магнезиев прах (пирофорен) |
| Spanish español | Magnesio en polvo (pirofórico) |
| Czech čeština | hořčík práškový nestabilizovaný |
| Danish dansk | magnesiumpulver (ustabiliseret) |
| German Deutsch | Magnesiumpulver (pyrophor) |
| Estonian eesti | magneesiumipulber (pürofoorne) |
| Greek ελληνικά | κόνις μαγνησίου (πυροφόρος) |
| English English | magnesium powder (pyrophoric) |
| French français | poudre (pyrophorique) de magnésium |
| Croatian hrvatski | magnezijev prah (piroforni) |
| Italian italiano | magnesio in polvere (piroforica) |
| Latvian latviešu | magnija pulveris (pirofors) |
| Lithuanian lietuvių | magnio milteliai (piroforiniai) |
| Hungarian magyar | magnéziumpor (pirofóros) |
| Maltese Malti | trab tal-manjeżju (piroforiku) |
| Dutch Nederlands | magnesiumpoeder (pyrofoor) |
| Polish polski | proszek magnezowy (piroforyczny) |
| Portuguese português | magnésio em pó (pirofórico) |
| Romanian română | magneziu pudră (piroforic) |
| Slovak slovenčina | práškový horčík (pyroforický) |
| Slovenian slovenščina | magnezijev prah (piroforen) |
| Finnish suomi | magnesiumjauhe (stabiloimaton) |
| Swedish svenska | magnesiumpulver (pyrofort) |
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
Magnesium powder (pyrophoric) GHS label elements
Everything CLP Annex VI fixes for Magnesium powder…, laid out the way it appears on a label. The greyed lines are the parts only the supplier can fill in.
Danger
Magnesium powder (pyrophoric)
- Catches fire spontaneously if exposed to air.
- In contact with water releases flammable gases which may ignite spontaneously.
- Keep away from heat, hot surfaces, sparks, open flames and other ignition sources. No smoking.
- Do not allow contact with air.
- Handle and store contents under inert gas/…
- Wear protective gloves/protective clothing/eye protection/face protection/hearing protection/…
- In case of fire:
- Dispose of contents/container to …
Supplier name, address and telephone number· Product identifier·Nominal quantity
Need this as an actual label? Open Magnesium powder… in the GHS label constructor →
07 · Health hazards
Magnesium powder (pyrophoric) health hazards and exposure limits
Magnesium powder (pyrophoric) hazard summary
Elemental magnesium can cause serious skin burns and magnesium fume may cause metal fume fever; [CHEMINFO MSDS] The normal range of serum magnesium is 1.7-2.4 mg/dL. The therapeutic level for toxemia is 5-7.4 mg/dL Sedation and hypotension occur at levels exceeding 8-12 mg/dL. Arrhythmias and muscular paralysis with respiratory arrest occur at levels exceeding 12 mg/dL. Patients with renal insufficiency taking magnesium-containing antacids or cathartics are at risk. [Olson, p. 301]
Source: Haz-Map, Information on Hazardous Chemicals and Occupational Diseases
08 · Physical and chemical properties
Magnesium powder (pyrophoric) 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.
Magnesium powder (pyrophoric) boiling point
| Property | Value | Conditions | Source |
|---|---|---|---|
| Boiling point | 1100 °C (2012 °F) | HSDB | |
| 1100 °C (2012 °F) | at 760 mmHg | CAMEO |
Magnesium powder (pyrophoric) melting point
| Property | Value | Conditions | Source |
|---|---|---|---|
| Melting point | 651 °C (1203.8 °F) | HSDB | |
| 650 °C (1202 °F) | CAMEO | ||
| 649 °C (1200.2 °F) | ICSC |
Magnesium powder (pyrophoric) density
| Property | Value | Conditions | Source |
|---|---|---|---|
| Density | 1.7 g/cm³ | ICSC | |
| 1.738 g/cm³ | at 20 °C | HSDB | |
| 1.74 g/cm³ | at 20 °C | CAMEO |
Magnesium powder (pyrophoric) solubility
| Property | Value | Conditions | Source |
|---|---|---|---|
| Solubility | INSOL IN COLD WATER, CHROMIUM TRIOXIDES; SOLUBLE IN MINERAL ACIDS | HSDB | |
| Insoluble but reactive in water, liberating hydrogen gas | HSDB | ||
| Solubility in water: reaction | ICSC |
Magnesium powder (pyrophoric) vapor pressure
| Property | Value | Conditions | Source |
|---|---|---|---|
| Vapor pressure | 0.0075 mmHg | at 428 °C | HSDB |
| 1 mmHg | Haz-Map |
Magnesium powder (pyrophoric) flash point
| Property | Value | Conditions | Source |
|---|---|---|---|
| Flash point | 500 °C (932 °F) | HSDB |
Magnesium powder (pyrophoric) autoignition temperature
| Property | Value | Conditions | Source |
|---|---|---|---|
| Autoignition temperature | 472.78 °C (883 °F) | HSDB | |
| 473 °C (883.4 °F) | ICSC |
Magnesium powder (pyrophoric) lower explosive limit (LEL)
| Property | Value | Conditions | Source |
|---|---|---|---|
| Lower explosive limit (LEL) | ... Powders form explosive mixtures with air that may be ignited by a spark. | HSDB | |
| ...MOLTEN METAL BURNS EXPLOSIVELY IN PRESENCE OF EXCESSIVE MOISTURE, AS IN MOULDING SAND. FIRE & EXPLOSION ARE OUTSTANDING HAZARDS IN MFR OF MAGNESIUM ALLOYS. | HSDB | ||
| Explosive limits , vol% in air: | ICSC |
Magnesium powder (pyrophoric) vapor density
| Property | Value | Conditions | Source |
|---|---|---|---|
| Vapor density | 0.84 (air = 1) | HSDB |
Magnesium powder (pyrophoric) corrosivity
| Property | Value | Conditions | Source |
|---|---|---|---|
| Corrosivity | Highly resistant | HSDB |
Values compiled from PubChem Laboratory Chemical Safety Summary. Temperatures converted to Fahrenheit for reference.
09 · Fire and explosion
Magnesium powder… 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.
Magnesium powder (pyrophoric) fire potential
MAGNESIUM FIRE: DO NOT FLARE UP VIOLENTLY UNLESS...MOISTURE PRESENT. DANGEROUS IN FORM OF DUST OR FLAKES, WHEN EXPOSED TO FLAME OR BY VIOLENT CHEM REACTION WITH OXIDIZING AGENTS. ...SOLID FORM IS DIFFICULT TO IGNITE...IT MUST BE HEATED ABOVE ITS MELTING POINT... FINELY DIVIDED FORM...MAY BE IGNITED BY SPARK OR FLAME...OR EVEN SPONTANEOUSLY WHEN...DAMP, PARTICULARLY WITH WATER-OIL EMULSION. DURING MACHINING, MAGNESIUM FIRES RESULT FROM USE OF DULL CUTTING TOOLS, MACHINING WITH LIGHT CUT AT HIGH SPEEDS OR RUBBING OF TOOL ON WORK AFTER CUTTING OPERATION IS FINISHED.
Source: Hazardous Substances Data Bank (HSDB)
10 · Handling and storage
Magnesium powder (pyrophoric) storage and handling
Magnesium powder (pyrophoric) safe storage
Fireproof. Dry. Well closed. Separated from other incompatible materials.
Source: ILO-WHO International Chemical Safety Cards (ICSCs)
Magnesium powder (pyrophoric) storage conditions
Detached storage must be used for finely divided materials. Must be stored in a dry location. Isolate from halogens, acids, and oxidizing materials.
Source: Hazardous Substances Data Bank (HSDB)
Magnesium powder (pyrophoric) incompatible materials
Incompatible with ethylene oxide, metal oxosalts, oxidants, and potassium carbonate.
Source: Hazardous Substances Data Bank (HSDB)
Planning storage for a mix of chemicals? Check Magnesium powder… in the storage compatibility matrix →
11 · Transport
Magnesium powder (pyrophoric) 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.
Magnesium powder (pyrophoric) under UN 1418 — shipping name, class and packing group
Europe · ADR 2025, Table A
| Proper shipping name (3.1.2) | Class | Classification code | PG | Labels (column 5) |
|---|---|---|---|---|
| MAGNESIUM POWDER or MAGNESIUM ALLOYS POWDER | 4.3 | WS | I | |
| MAGNESIUM POWDER or MAGNESIUM ALLOYS POWDER | 4.3 | WS | II | |
| MAGNESIUM POWDER or MAGNESIUM ALLOYS POWDER | 4.3 | WS | III | |
Source: ADR 2025, Table A of Chapter 3.2 · ECE/TRANS/352 Vol. I (UNECE). Class 4.3 is “Substances which, in contact with water, emit flammable 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) |
|---|---|---|---|
| Magnesium, powder or Magnesium alloys, powder | 4.3 | I | |
| Magnesium, powder or Magnesium alloys, powder | 4.3 | II | |
| Magnesium, powder or Magnesium alloys, powder | 4.3 | III | |
Source: 49 CFR 172.101 Hazardous Materials Table · eCFR, revision 2026-08-03. Class 4.3 is “Dangerous when wet material” (49 CFR 173.2).
12 · Questions
Magnesium powder (pyrophoric) — frequently asked questions
What is the CAS number of Magnesium powder (pyrophoric)?
The CAS number of Magnesium powder (pyrophoric) is 7439-95-4. Its EC number is 231-104-6.
What does a Magnesium powder (pyrophoric) label have to show?
Under CLP Annex VI the label for Magnesium powder (pyrophoric) carries the pictogram Flame and the signal word is Danger.
Is Magnesium powder (pyrophoric) flammable?
Yes. CLP Annex VI assigns Magnesium powder (pyrophoric) H250 and H260 — catches fire spontaneously if exposed to air. The flash point reported for it is 500 °C (932 °F) (HSDB).
Is Magnesium powder (pyrophoric) a carcinogen?
CLP Annex VI records no harmonised carcinogenicity classification for Magnesium powder (pyrophoric). 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 Magnesium powder (pyrophoric)?
The boiling point reported for Magnesium powder (pyrophoric) is 1100 °C (2012 °F) (HSDB).
What is the melting point of Magnesium powder (pyrophoric)?
The melting point reported for Magnesium powder (pyrophoric) is 651 °C (1203.8 °F) (HSDB).
How should Magnesium powder (pyrophoric) be stored?
Detached storage must be used for finely divided materials. Must be stored in a dry location. Isolate from halogens, acids, and oxidizing materials. (Hazardous Substances Data Bank (HSDB))
Nearby
Substances next to Magnesium powder…
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