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

Sulfur

Sulfur is yellow orthorhombic crystals and is odorless.

CAS 7704-34-9 S 32.07 g/mol Warning

Sulfur Safety Data Sheet →

01 · Identification

What Sulfur is

Sulfur is yellow orthorhombic crystals and is odorless. Its molecular formula is S and its molecular weight is 32.07 g/mol. It boils at 445 °C, melts at 95.3 °C.

Under the GHS it carries the signal word Warning.

02 · Identifiers

Sulfur identifiers and molecular data

Sulfur CAS number and EC number

CAS number7704-34-9
EC number231-722-6
Index number (CLP Annex VI)016-094-00-1

Sulfur molecular formula and molecular weight

Molecular formulaS
Molecular weight32.07 g/mol

Other names for Sulfur

  • sulphur
  • brimstone
  • Sulfur, Dry
  • Sulfur, Molten
  • Sulphur, Molten

03 · GHS classification

Sulfur hazard classification

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

Sulfur pictograms and signal word

Signal wordWarning

Sulfur hazard class and category

GHS hazard classes Sulfur falls into
Hazard class Category From code Pictogram
Skin corrosion/irritation GHS chapter 3.2 Category 2 H315 GHS07

Sulfur hazard statements (H-codes)

Hazard statements assigned to Sulfur
CodeHazard statement
H315 Causes skin irritation.

This page lists only the codes assigned to Sulfur. 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 Sulfur

Our own Sulfur safety data sheet walks through all sixteen sections of the published data. What it is not is the document an inspector asks for: an SDS is issued for a product by its supplier, so the sheet covering the grade actually standing in your store exists only in that supplier’s version. Collecting those and keeping them current as suppliers revise them is a separate job.

04 · Precautionary statements

Sulfur precautionary statements

CLP Annex VI assigns 6 precautionary statements to Sulfur. 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

Sulfur name in 22 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 сяра
Spanish español Azufre
Czech čeština síra
Danish dansk svovl
German Deutsch Schwefel
Estonian eesti väävel
Greek ελληνικά θείο
English English sulfur
French français soufre
Croatian hrvatski sumpor
Italian italiano zolfo
Latvian latviešu sērs
Lithuanian lietuvių siera
Hungarian magyar kén
Maltese Malti kubrit
Dutch Nederlands zwavel
Polish polski siarka
Romanian română sulf
Slovak slovenčina síra
Slovenian slovenščina žveplo
Finnish suomi rikki
Swedish svenska svavel

22 of the 23 language editions carry this entry; it is absent from Portuguese. That is a property of the regulation, not a gap in this table — editions do occasionally differ in which entries they print. 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

Sulfur GHS label elements

Everything CLP Annex VI fixes for Sulfur, laid out the way it appears on a label. The greyed lines are the parts only the supplier can fill in.

GHS07 Exclamation mark pictogram

Warning

Sulfur

  • Causes skin irritation.
  • Wash thoroughly after handling.
  • Wear protective gloves/protective clothing/eye protection/face protection/hearing protection/
  • IF ON SKIN:
  • Get medical advice/attention.
  • If skin irritation occurs:
  • Wash with plenty of water/

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

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

07 · Health hazards

Sulfur health hazards and exposure limits

Sulfur hazard summary

Burning can release toxic gases; Molten sulfur can cause severe burns; [CAMEO] Dust explosions can result when powder is mixed with air. [ICSC]

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

08 · Physical and chemical properties

Sulfur 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.

Sulfur boiling point

Property Value Conditions Source
Boiling point 444.61 °C (832.3 °F) HSDB
445 °C (833 °F) ICSC

Sulfur melting point

Property Value Conditions Source
Melting point 95.3 °C (203.5 °F) Sulfur rhombic transforms to monoclinic HSDB
106.8 °C (224.2 °F) gamma-Sulfur HSDB
120 °C (248 °F) amorphous ICSC

Sulfur density

Property Value Conditions Source
Density 2.07 g/cm³ rhombic HSDB
2.06 g/cm³ HSDB
1.96 g/cm³ HSDB

Sulfur solubility

Property Value Conditions Source
Solubility Insoluble in water; slightly soluble in ethanol, benzene, ethyl ether; soluble in carbon disulfide HSDB

Sulfur vapor pressure

Property Value Conditions Source
Vapor pressure 0.00000395 mmHg at 30.4 °C HSDB

Sulfur flash point

Property Value Conditions Source
Flash point 207.22 °C (405 °F) HSDB
160 °C (320 °F) ICSC

Sulfur autoignition temperature

Property Value Conditions Source
Autoignition temperature 232.22 °C (450 °F) HSDB
232 °C (449.6 °F) ICSC

Sulfur lower explosive limit (LEL)

Property Value Conditions Source
Lower explosive limit (LEL) 35 % by volume HSDB
Lower flammable limit for sulfur dust in air is 35 mg/L ... . HSDB

Sulfur vapor density

Property Value Conditions Source
Vapor density Density of vapor/density of air, 470 °C: 7.837 at 470 °C HSDB

Sulfur critical temperature and pressure

Property Value Conditions Source
Critical temperature and pressure 1040 °C (1904 °F) HSDB

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

09 · Fire and explosion

Sulfur 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.

Sulfur fire potential

Vapors given off during melting of sulfur may contain sufficient hydrogen sulfide & carbon disulfide to permit ignition of air/vapor mixture on contact with hot surface; such ignition may result in transmission of flames to molten sulfur. ... Sulfur is poor conductor of electricity & tends to develop charges of static electricity during transport or processing; static discharge may lead to ignition of sulfur dust. Fires in heaps of sulfur are frequent & insidious since they may break out again even after original conflagration has ... Been extinguished.

Source: Hazardous Substances Data Bank (HSDB)

Corrosivity

Sulfur is not considered corrosive to the usual construction materials. However, acid-generating impurities, which may be introduced in handling and storage, create corrosive conditions.

Source: HSDB

10 · Handling and storage

Sulfur storage and handling

Sulfur reactive group

CAMEO Chemicals places Sulfur in the reactive group Reducing Agents, Strong. Compatibility with other chemicals is worked out from the group, not from the individual substance — which is why two substances you have never seen react can still be flagged as a pair that must be separated.

A reactive group is a CAMEO Chemicals (US NOAA) grouping, not a GHS hazard class: it has no code, no category and no legal force. It is what the storage compatibility matrix on this site computes from.

Sulfur safe storage

Fireproof. Separated from strong oxidants.

Source: ILO-WHO International Chemical Safety Cards (ICSCs)

Sulfur storage conditions

Store in cool, dry, well-ventilated location. Separate from chlorates, nitrates, other oxidizing materials, and hydrocarbons.

Source: Hazardous Substances Data Bank (HSDB)

Sulfur incompatible materials

Reacts with oxidizing materials.

Source: Hazardous Substances Data Bank (HSDB)

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

11 · Questions

Sulfur — frequently asked questions

What is the CAS number of Sulfur?

The CAS number of Sulfur is 7704-34-9. Its EC number is 231-722-6.

What is the chemical formula of Sulfur?

The molecular formula of Sulfur is S and its molecular weight is 32.07 g/mol.

What does a Sulfur label have to show?

Under CLP Annex VI the label for Sulfur carries the pictogram Exclamation mark and the signal word is Warning.

Is Sulfur flammable?

CLP Annex VI assigns Sulfur 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. The flash point reported for it is 207.22 °C (405 °F) (HSDB).

Is Sulfur a carcinogen?

CLP Annex VI records no harmonised carcinogenicity classification for Sulfur. 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 Sulfur?

The boiling point reported for Sulfur is 444.61 °C (832.3 °F) (HSDB).

What is the melting point of Sulfur?

The melting point reported for Sulfur is 95.3 °C (203.5 °F), Sulfur rhombic transforms to monoclinic (HSDB).

How should Sulfur be stored?

Store in cool, dry, well-ventilated location. Separate from chlorates, nitrates, other oxidizing materials, and hydrocarbons. (Hazardous Substances Data Bank (HSDB))

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