Sulfate or Sulphate: INCI Spelling Choices That Matter

Somebody on your label design team writes "Sodium Laureth Sulphate" because that's how it was spelled on last year's packaging, and somebody filing the CNF types "Sodium Laureth Sulfate" because that's the spelling on the supplier's certificate of analysis. Neither person is wrong exactly, but now you've got two spellings of the same ingredient floating around your compliance paperwork, and that's the kind of small inconsistency that makes an ingredient harder to verify at a glance.

Why both spellings exist

INCI names originated from a nomenclature system with international roots, and American versus British English spelling conventions carried over into ingredient naming in ways that never fully got standardized into one single spelling worldwide. "Sulfate" is the American spelling, "sulphate" is the British spelling, and you'll see both used depending on which regulatory tradition a document was originally written for. The same split shows up in a handful of other ingredient-adjacent terms too, though sulfate/sulphate is by far the most common one makers run into, since it appears in some of the most widely used surfactants in the industry, including Sodium Lauryl Sulfate and Sodium Laureth Sulfate.

Critically, this is a spelling variant, not two different chemicals. Sodium Laureth Sulfate and Sodium Laureth Sulphate refer to the same substance, matched to the same CAS number. The confusion isn't about chemistry, it's about which text string ends up on which document.

Why consistency matters more than which spelling you pick

Health Canada's Cosmetic Notification System and Hotlist references generally follow the standard INCI naming conventions used in the current, authoritative ingredient dictionaries, and for a filing to be checked cleanly against the Cosmetic Ingredient Hotlist, the name you enter needs to match how that ingredient is recognized in the system you're filing through. If you've spelled it one way on your CNF and a different way on your product label, that's not necessarily a hard failure by itself, but it does create an unnecessary mismatch that makes any manual cross-check, whether it's a reviewer, a retailer's compliance team, or your own future self six months from now, take longer than it should.

The practical fix isn't "always use the American spelling" or "always use the British spelling." It's pick one spelling per ingredient across your entire operation, your formula sheet, your CNF entries, and your product labels, and stay consistent.

A quick reference for the common ones

Note that some sulfate-family ingredients have more than one associated CAS number depending on the exact ethoxylation or salt form, which is a separate issue from spelling but worth double-checking against your specific supplier's certificate of analysis rather than assuming one CAS number covers every version of an ingredient with a similar name.

A habit worth building

When you first build your formula sheet for a product, decide on your spelling convention and write it down somewhere your whole team can see it, even if that's just a note at the top of a shared spreadsheet. New hires, new suppliers, and new label designers will each bring their own spelling habits in, and a five-second glance at a style note prevents the slow drift where your CNF says one thing and your label says another.

Cosmetic Comply normalizes ingredient names against standard INCI references when it matches your formula, so a sulfate versus sulphate spelling difference gets reconciled to the same underlying ingredient and CAS number automatically rather than being treated as two separate unknowns.