Substance profile
Phosphorus
Phosphorus exists in three main allotropic forms: white, black, and red. It has a garlic-like odor.
01 · Identification
What Phosphorus is
Phosphorus exists in three main allotropic forms: white, black, and red. It has a garlic-like odor. Its molecular formula is P and its molecular weight is 30.974 g/mol. It boils at 280 °C, melts at 44.1 °C.
Under the GHS it carries the signal word Danger. It is classed as hazardous Air Pollutants (HAPs).
02 · Identifiers
Phosphorus identifiers and molecular data
Phosphorus CAS number and EC number
Phosphorus molecular formula and molecular weight
Other names for Phosphorus
- red phosphorus
03 · GHS classification
Phosphorus hazard classification
Harmonised classification under CLP Annex VI. This is the legally binding classification in the EU; other jurisdictions may differ.
Phosphorus pictograms and signal word
Phosphorus hazard class and category
| Hazard class | Category | From code | Pictogram |
|---|---|---|---|
| Flammable solids GHS chapter 2.7 | Category 1 or 2 | H228 | GHS02 |
| Hazardous to the aquatic environment - chronic GHS chapter 4.1 | Category 3 | H412 | — |
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.
Phosphorus hazard statements (H-codes)
| Code | Hazard statement |
|---|---|
| H228 | Flammable solid. |
| H412 | Harmful to aquatic life with long lasting effects. |
This page lists only the codes assigned to Phosphorus. 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 Phosphorus
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 Phosphorus 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
Phosphorus precautionary statements
CLP Annex VI assigns 2 precautionary statements to Phosphorus. 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
Phosphorus 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 | червен фосфор |
| Spanish español | Fósforo rojo |
| Czech čeština | fosfor červený |
| Danish dansk | phosphor, rød |
| German Deutsch | Roter Phosphor |
| Estonian eesti | punane fosfor |
| Greek ελληνικά | ερυθρός φωσφόρος |
| English English | red phosphorus |
| French français | phosphore rouge |
| Croatian hrvatski | crveni fosfor |
| Italian italiano | fosforo rosso |
| Latvian latviešu | sarkanais fosfors |
| Lithuanian lietuvių | raudonasis fosforas |
| Hungarian magyar | vörös foszfor |
| Maltese Malti | fosforu aħmar |
| Dutch Nederlands | rode fosfor |
| Polish polski | fosfor czerwony polifosfor |
| Portuguese português | fósforo vermelho |
| Romanian română | fosfor roșu |
| Slovak slovenčina | červený fosfor |
| Slovenian slovenščina | rdeči fosfor |
| Finnish suomi | fostori, punainen |
| Swedish svenska | fosfor, röd |
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
Phosphorus GHS label elements
Everything CLP Annex VI fixes for Phosphorus, laid out the way it appears on a label. The greyed lines are the parts only the supplier can fill in.
Danger
Phosphorus
- Flammable solid.
- Harmful to aquatic life with long lasting effects.
- Avoid release to the environment.
- Dispose of contents/container to …
Supplier name, address and telephone number· Product identifier·Nominal quantity
Need this as an actual label? Open Phosphorus in the GHS label constructor →
07 · Health hazards
Phosphorus health hazards and exposure limits
Phosphorus hazard summary
White phosphorus is a colorless, white, or yellow waxy solid with a garlic-like odor. It does not occur naturally, but is manufactured from phosphate rocks. White phosphorus reacts rapidly with oxygen, easily catching fire at temperatures 10 to 15 degrees above room temperature. White phosphorus is used by the military in various types of ammunition, and to produce smoke for concealing troop movements and identifying targets. It is also used by industry to produce phosphoric acid and other chemicals for use in fertilizers, food additives, and cleaning compounds. Small amounts of white phosphorus were used in the past in pesticides and fireworks.
Source: Agency for Toxic Substances and Disease Registry (ATSDR)
Phosphorus carcinogenicity classification
Cancer Classification: Group D Not Classifiable as to Human Carcinogenicity
Source: Hazardous Substances Data Bank (HSDB)
CLASSIFICATION: D; not classifiable as to human carcinogenicity. BASIS FOR CLASSIFICATION: Based on no data in humans or animals. HUMAN CARCINOGENICITY DATA: None. ANIMAL CARCINOGENICITY DATA: None.
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.
Phosphorus occupational exposure limits
| Limit | Value | Source |
|---|---|---|
| PEL | 0.1 mg/m³ | Occupational Safety and Health Administration (OSHA) |
| REL | 0.1 mg/m³ | Occupational Safety and Health Administration (OSHA) |
| IDLH | 5 mg/m3 [From NPG: Phosphorus (yellow)] (NIOSH, 2024) | CAMEO Chemicals |
| IDLH | 5 mg/cu m | Hazardous Substances Data Bank (HSDB) |
| IDLH | 5 mg/m³ | Occupational Safety and Health Administration (OSHA) |
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
Phosphorus 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.
Phosphorus boiling point
| Property | Value | Conditions | Source |
|---|---|---|---|
| Boiling point | 280 °C (536 °F) | HSDB | |
| 280 °C (536 °F) | at 760 mmHg | CAMEO | |
| 448.28 °C (838.9 °F) | at 760 mmHg | CAMEO |
Phosphorus melting point
| Property | Value | Conditions | Source |
|---|---|---|---|
| Melting point | 44.1 °C (111.4 °F) | HSDB | |
| 610 °C (1130 °F) | HSDB | ||
| 44 °C (111.2 °F) | CAMEO |
Phosphorus density
| Property | Value | Conditions | Source |
|---|---|---|---|
| Density | 1.83 g/cm³ | alpha-form | HSDB |
| 2.691 g/cm³ | HSDB | ||
| 2.34 g/cm³ | CAMEO |
Phosphorus solubility
| Property | Value | Conditions | Source |
|---|---|---|---|
| Solubility | 0.33 mg/100 g water at 15 °C; 2.7 g/100 g benzene at 15 °C; 89.8 g/100 g carbon disulfide at 10 °C | at 15 °C | HSDB |
Phosphorus vapor pressure
| Property | Value | Conditions | Source |
|---|---|---|---|
| Vapor pressure | 0.03 mmHg | OSHA | |
| 0.026 mmHg | at 20 °C | HSDB |
Phosphorus autoignition temperature
| Property | Value | Conditions | Source |
|---|---|---|---|
| Autoignition temperature | 260 °C (500 °F) | HSDB | |
| 400 °C (752 °F) | above this value | CAMEO |
Phosphorus lower explosive limit (LEL)
| Property | Value | Conditions | Source |
|---|---|---|---|
| Lower explosive limit (LEL) | White-yellow: Can be ignited under almost all normal temperature conditions. Red: Material that must be preheated before ignition can occur. (EPA, 1998) | CAMEO |
Phosphorus upper explosive limit (UEL)
| Property | Value | Conditions | Source |
|---|---|---|---|
| Upper explosive limit (UEL) | White-yellow: Can be ignited under almost all normal temperature conditions. Red: Material that must be preheated before ignition can occur. (EPA, 1998) | CAMEO |
Phosphorus vapor density
| Property | Value | Conditions | Source |
|---|---|---|---|
| Vapor density | 4.77 (air = 1) | HSDB |
Phosphorus critical temperature and pressure
| Property | Value | Conditions | Source |
|---|---|---|---|
| Critical temperature and pressure | 721 °C (1329.8 °F) | HSDB |
Values compiled from PubChem Laboratory Chemical Safety Summary. Temperatures converted to Fahrenheit for reference.
09 · Fire and explosion
Phosphorus 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.
Phosphorus fire potential
White: ignites at approx 30 °C in moist air; ignition temp is higher when air is dry. Black: does not catch fire spontaneously. Red: catches fire when heated in air to approx 260 °C and burns with formation of the pentoxide. Burns when heated in atmosphere of chlorine.
Source: Hazardous Substances Data Bank (HSDB)
Solubility
Black: Insoluble in organic solvents; White: Insoluble in water, slightly soluble in benzene, ethanol, and chloroform, soluble in carbon disulfide; Red: Insoluble in water and organic solvents.
Source: HSDB
Solubilities in water: one part/300,000 parts water; in abs alc: one g/400 mL; in abs ether: one g/102 mL; in CHCl3: one g/40 mL; in benzene: one g/35 mL; in CS2: one g/0.8 mL. Solubility in oils: one gram phosphorus dissolves in 80 ml olive oil, 60 ml oil of turpentine, about 100 mL almond oil.
Source: HSDB
10 · Handling and storage
Phosphorus storage and handling
Phosphorus storage conditions
Separate from air, oxidizing materials, combustibles. Always keep container closed, with material under water or inert gas. /Phosphorus, white, molten/
Source: Hazardous Substances Data Bank (HSDB)
Phosphorus incompatible materials
Red: Avoid uncontrolled contact with oxidizing agents ... or with strong alkaline hydroxides. Can react violently with oxidizing agent in presence of air & moisture, liberating phosphorus acids & toxic, spontaneously flammable phosphine gas.
Source: Hazardous Substances Data Bank (HSDB)
Phosphorus reactivity
PHOSPHORUS, AMORPHOUS (RED OR VIOLET) is a reducing agent. Much less reactive than the allotropic white phosphorus. Reacts strongly with bromine trifluoride. [Mellor 2:113. 1946-47]. Explodes on contact with bromoazide.
Source: CAMEO Chemicals
Planning storage for a mix of chemicals? Check Phosphorus in the storage compatibility matrix →
11 · Questions
Phosphorus — frequently asked questions
What is the CAS number of Phosphorus?
The CAS number of Phosphorus is 7723-14-0. Its EC number is 231-768-7.
What is the chemical formula of Phosphorus?
The molecular formula of Phosphorus is P and its molecular weight is 30.974 g/mol.
What does a Phosphorus label have to show?
Under CLP Annex VI the label for Phosphorus carries the pictogram Flame and the signal word is Danger.
Is Phosphorus flammable?
Yes. CLP Annex VI assigns Phosphorus H228 — flammable solid.
Is Phosphorus a carcinogen?
CLP Annex VI records no harmonised carcinogenicity classification for Phosphorus. 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 Phosphorus?
The US occupational exposure limit reported for Phosphorus is 0.1 mg/m³ (Occupational Safety and Health Administration (OSHA)). 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 Phosphorus?
The boiling point reported for Phosphorus is 280 °C (536 °F) (HSDB).
What is the melting point of Phosphorus?
The melting point reported for Phosphorus is 44.1 °C (111.4 °F) (HSDB).
How should Phosphorus be stored?
Separate from air, oxidizing materials, combustibles. Always keep container closed, with material under water or inert gas. /Phosphorus, white, molten/ (Hazardous Substances Data Bank (HSDB))
Nearby
Substances next to Phosphorus
Keep going: substances starting with P, or search the whole database by name, CAS number, pictogram or signal word.