UN chemicals meeting bans chlorpyrifos and 2 other pollutants, with caveats

Meetings of three major United Nations chemical conventions wrapped last week, with an agreement for new global restrictions on three persistent organic pollutants (POPs)—chlorpyrifos, medium-chain chlorinated paraffins, and long-chain perfluorocarboxylic acids. But some members of the Conference of the Parties (COP) to the Basel, Rotterdam, and Stockholm conventions are unhappy with what they call a long list of exemptions to the bans. And in an unprecedented move, negotiators added a new use exemption for UV-328, an ultraviolet stabilizer banned in 2023.

“For all of the COPs’ progress, we continued to see attempts from certain Parties to whittle down the treaties’ effectiveness,” David Azoulay, environmental health program director at the Center for International Environmental Law, says in a statement. “Interventions showed a brazen, continued willingness to deny scientific findings and circumvent scientific review on requests for exemptions,” he says.

Under the Stockholm Convention, negotiators voted to eliminate worldwide use of the pesticide chlorpyrifos, medium-chain chlorinated paraffins (MCCPs), and long-chain perfluorocarboxylic acids (LC-PFCAs). Chlorpyrifos is an organophosphate pesticide that’s toxic to animals and suspected of having detrimental developmental effects in humans. It is banned in some countries but allowed for critical uses on 11 food and feed crops in the US. MCCPs are plasticizers and flame retardants that can cause liver, kidney, and thyroid gland harm in humans. LC-PFCAs are a class of per- and polyfluoroalkyl substances (PFAS) generated in the manufacture and incineration of other PFAS compunds, and are harmful to the liver and to reproductive, endocrine, and immune systems in humans.

But negotiators also agreed that MCCPs can still be used in solid woven conveyor belts in some mines, and flexible polyvinyl chloride foam for thermal insulation. This type of foam is found in window frames and flooring, but negotiators did not allow it for applications in indoor living spaces. COP participants also agreed to review these uses and exemptions at the next two COPs. They also allowed exemptions for LC-PFCAs in replacement semiconductors for combustion engine–powered vessels and vehicles that are no longer being manufactured.

During the last combined COPs in 2023, when UV-328 was banned, delegates from Ethiopia proposed to add an exemption for its use in aircraft sealants and adhesives. In 2024, the aircraft maker Boeing appealed the addition of the compound to a European Union POPs list, saying that the company’s efforts to find a replacement for UV-328 were delayed. Negotiators in Geneva last week agreed to the exemption but set an expiration date at the end of 2030. Environmental groups said that even though this exemption is limited in scope, it could set a dangerous precedent for revisiting restrictions that had been agreed.

“Once the science has demonstrated that [these substances] pose unacceptable threats to our health and the environment, the decision to eliminate them should not be revised,” Therese Karlsson, science adviser for the advocacy group International Pollutants Elimination Network, says in a statement. Doing so potentially undermines the convention’ integrity and scientific basis, she says.

The American Chemistry Council and the European Chemical Industry Council both declined to comment on the outcome of these COPs.

The COPs took place with many negotiators looking ahead to the resumed session of the Intergovernmental Negotiating Committee on Plastic Pollution (INC-5.2), scheduled for August 5–14 in Geneva. That process aims to establish a legally binding global treaty on plastic pollution, including marine impacts.