On 30 May 2023, the European Commission announced its decision to adopt the proposal amending Annex I to Regulation (EU) 2019/1021, confirming the inclusion of PFHxS and its salts and related compounds in the list of prohibited substances under the POPs Regulation. Once the control requirement is officially published, the list of prohibited substances in Annex I of the EU POPs Regulation will increase from 28 to 29 entries.

Previously, because of its significant hazard to the environment and human health, PFHxS and its salts and related compounds were officially listed under the Stockholm Convention. In early 2023 the European Commission proposed listing perfluorohexane sulfonic acid (PFHxS) and its salts and related compounds in Annex I of the POPs Regulation for control, and it is on the basis of that proposal that the inclusion in the prohibited substances list has now been confirmed.

The entry proposed for addition to Annex I of the POPs Regulation is as follows:

Substance

Perfluorohexane sulfonic acid (PFHxS) and its salts and related compounds

CAS No. 355-46-4 and others

Restriction conditions

(1) For the purposes of this entry, Article 4(1)(b) applies where the concentration of PFHxS or any of its salts in substances, mixtures or articles is 0.025 mg/kg (0.0000025%) or less.

(2) For the purposes of this entry, Article 4(1)(b) shall apply where the sum of the concentrations of all PFHxS-related substances in substances, mixtures or articles is 1 mg/kg (0.0001%) or less.

(3) For the purposes of this entry, Article 4(1)(b) shall apply where the concentration of PFHxS and PFHxS-related compounds in concentrated firefighting foam mixtures, or in mixtures used to produce other firefighting foam mixtures, is 0.1 mg/kg (0.00001%) or less; this exemption shall be reviewed by the Commission within three years of entry into force with a view to lowering the limit.

About PFHxS

PFHxS is one of the per- and polyfluoroalkyl substances (PFAS) and can be used as a substitute for perfluorooctane sulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) in areas such as firefighting foams, metal plating, textiles, leather, polishes, cleaning detergents, coatings, paper products and electronics and semiconductor manufacturing. However, because of its high persistence and bioaccumulation, it seriously threatens the environment and human health and currently attracts close attention worldwide.