Sulfur vs. Sulphur
Cambridge records “sulfur” and notes UK also “sulphur”; IUPAC’s English periodic-table spelling is “sulfur.”
“Sulfur” is IUPAC’s English element spelling and is widely used internationally; “sulphur” remains a documented UK variant in general English.
Key details
Choose the right form
| Context | Choose | Decision |
|---|---|---|
| scientific / standards-based English | sulfur | Use the IUPAC English element spelling. |
| general UK English where the traditional variant is acceptable | sulphur | Recognize the documented UK variant. |
| mixed international technical audience | sulfur | Prefer the standards-body spelling for consistency unless house style requires otherwise. |
Quick tests
Audience-and-standard test
Is this scientific or technical writing that should follow IUPAC element spelling?
If yes: Use “sulfur.”
If no: In general UK English, “sulphur” remains a documented variant; follow house style and audience.
Caveat: This is a spelling and standards choice, not a difference in the chemical element itself.
Examples
Sulfur has the chemical symbol S.
The IUPAC English spelling is “sulfur.”
The museum label uses the traditional British spelling sulphur.
“Sulphur” remains a documented UK variant in general English.
For an international chemistry report, use sulfur consistently.
The standards-body spelling provides a clear technical default.
Further guidance
Core difference
Use “sulfur” when following IUPAC/scientific nomenclature or a style that specifies it; “sulphur” remains a documented UK variant in general language.
Fast Test
Match the form to the intended meaning, regional convention, or required house style, then keep that choice consistent.
Variant Boundary
A standards-body spelling preference does not make every occurrence of the documented UK variant an ordinary-language error.
Sources and evidence
Sources are shown with the role they play in this guide. Historical or style-sensitive claims are kept within the evidence boundary described above.
- Sulfur — Cambridge Dictionary (opens in a new tab)Cambridge Dictionary · Sulfur element name with UK also sulphur
- Sulphur — Cambridge Dictionary (opens in a new tab)Cambridge Dictionary · UK spelling variant of sulfur
- Periodic Table — IUPAC (opens in a new tab)IUPAC · IUPAC English element spellings include sulfur and aluminium