Norway has nominated perfluorohexane sulfonic acid (also known as perfluorohexane sulfonate or PFHxS, Chemical Abstracts Service (CAS) # 355-46-4) for inclusion in the Stockholm Convention on Persistent Organic Pollutants (Convention). This appears to be the only new proposal to list a new substance in the Convention that has been submitted in time for review during the current year.

The Convention is a global treaty that generally prohibits the production, use, and trade of listed persistent organic pollutants—toxic, long-lasting, and widely distributed chemicals that bioaccumulate in living organisms—in the 181 party states. Although the United States is not a party to the Convention, a Convention listing affects global trade in chemicals and the products and wastes that contain those chemicals and therefore impacts companies in the United States.

The nomination is not yet public, so the precise scope (e.g., whether it includes multiple salts) of the nomination is not known. The nomination will presumably include one or more CAS registry numbers that will define the scope of the proposal.

PFHxS is a perfluoroalkyl substance (PFAS), similar in chemical class to perfluorooctane sulfonate (PFOS), which is already listed in the Convention. In general, PFASs have fire, oil, stain, grease, and water resistant properties; thus, they are used in such products as firefighting foam, carpet treatments, nonstick cookware, upholstered furniture, and food packaging. PFASs also serve as processing aids in fluoropolymer manufacturing and are used in chrome plating. Consequently, listing PFHxS in the Convention might affect the aerospace, automotive, construction, electronics, textile, cleaning supply, chemical processing, and semiconductor industries if they use the chemical in their products, supply chains, or manufacturing operations.

In the European Union, PFHxS is currently the subject of ongoing review as a potential substance of very high concern, which could eventually lead to authorization requirements under the Registration, Evaluation, Authorisation, and Restriction of Chemicals (REACH) regulation.

A party nomination is the first of six steps in listing a chemical in the Convention. The second step is for the Persistent Organic Pollutants Review Committee (POPRC) to complete a screening review, likely in October 2017. The POPRC reviews the nomination to ensure that the persistence, bioaccumulation, long-range environmental transport, and toxicity screening criteria are satisfied.

Third, the POPRC will conduct a risk profile review to ascertain whether the nominated chemical is likely to lead to significant adverse effects due to its long-range transport, thereby warranting global action. The risk profile is prepared at least a year after the screening review, probably in October 2018.

Fourth, the POPRC completes a risk management review at least a year after the risk profile review (expected in October 2019). At this stage, the POPRC will consider which annex, control measures, and exemptions should apply when listing the chemical and make a recommendation to the Conference of the Parties (COP), which comprises each government that is a party to the Convention. Chemicals can either be listed in Annex A (eliminating production and use) or Annex B (restricting production and use).

Fifth, the COP considers the POPRC’s recommendation and determines whether to list the chemical and the content of the listing. As the COP only meets once every two years, this step may be completed six to 18 months after the risk management review. We anticipate that the COP will make its determination in spring 2021. 

Sixth, the decision to list the chemical automatically takes effect in most party nations a year after the amendment is translated and circulated (in fall 2022 at the earliest). Other parties must ratify the amendment before it enters into force. In total, the process to list a chemical takes about 3.5 to 4.5 years following the nomination. Virtually all nominated chemicals have been listed to date; consequently, PFHxS will likely become a listed chemical under the Convention. Companies that use PFHxS in products or production processes should closely follow and consider engaging in the decision-making process under the Convention. B&D can provide more information about this process and how you can engage upon request.