Allowed in EU

Butyrolactonethiol

A cosmetic ingredient used as hair waving or straightening, reducing in skincare, haircare, and personal-care products sold in the European Union.

What is it?

2(3H)-Furanone, Dihydro-3-Mercapto-; Butyric acid, 4-hydroxy-2-mercapto-, gamma-lactone

What does it do?

Butyrolactonethiol is listed in the EU cosmetic ingredient inventory with the following declared functions:

  • Hair waving or straightening

    permanently changes the shape of hair through chemical reduction and re-oxidation of the hair's disulfide bonds

  • Reducing

    a reducing agent — donates electrons to break chemical bonds, used in perms and depilatories

EU regulatory status

Butyrolactonethiol is allowed for use in cosmetic products in the European Union under Regulation 1223/2009. It is not subject to a specific Annex restriction at the time of writing.

Frequently asked questions

What is Butyrolactonethiol?

Butyrolactonethiol is a cosmetic ingredient catalogued in the EU CosIng database. 2(3H)-Furanone, Dihydro-3-Mercapto-; Butyric acid, 4-hydroxy-2-mercapto-, gamma-lactone

Is Butyrolactonethiol allowed in cosmetics in the EU?

Yes. Butyrolactonethiol is allowed for use in cosmetic products in the EU under Regulation 1223/2009.

What does Butyrolactonethiol do in cosmetic products?

Butyrolactonethiol is declared in the EU cosmetic ingredient inventory with these functions: hair waving or straightening, reducing.

What is the CAS number of Butyrolactonethiol?

The CAS (Chemical Abstracts Service) number for Butyrolactonethiol is 14032-62-3.

Related ingredients

Source: EU CosIng database (European Commission). This page is derived from public-sector information published by the European Commission. · Last updated: 15/10/2010