Mercaptoimidazoline and 2-mercaptoimidazoline

Also known as ethylene thiourea, this was used as an accelerator in the manufacture of rubber. The FDA prohibits it in rubber articles intended to contact food, so the restriction applies to equipment and packaging rather than to food itself.

Where it is and isn’t permitted

Status of Mercaptoimidazoline and 2-mercaptoimidazoline by jurisdiction. Every jurisdiction this site covers is listed, including those where the substance does not appear.
JurisdictionStatusScope and limitsCitation
United StatesFood and Drug AdministrationProhibited

Prohibited from indirect addition to human food through food-contact surfaces.

21 CFR 189.250retrieved 2026-09-07
Codex AlimentariusCodex Alimentarius Commission / JECFANot listedDoes not appear on this jurisdiction’s permitted list. That is not the same as being prohibited.

What it is made from

A synthetic sulfur-containing heterocycle made from ethylenediamine and carbon disulfide. It also arises as a breakdown product of the ethylenebisdithiocarbamate fungicides, which is a separate regulatory question from this one.

Every name it appears under

1 recorded name. A label may use any of them.

As it appears in regulation

  • Mercaptoimidazoline and 2-mercaptoimidazoline

Hazard reference values

No reference value for this substance in the sources we hold.

Evidence and how bodies read it

Studies, and the differing conclusions regulators drew from them, are curated by hand rather than machine-read, and none has been written for this substance yet.

Sources for this page

  • ecfr retrieved 2026-09-07

Full licence terms and publisher details on Sources. How this page is built and updated: Method.

Machine-readable:/api/v1/additives/mercaptoimidazoline-and-2-mercaptoimidazoline.json