On 12 May 2023, the eleventh Conference of the Parties to the Stockholm Convention decided to eliminate the use of three persistent organic pollutants, namely the pesticide methoxychlor, the industrial chemical Dechlorane Plus and UV-328.

Persistent organic pollutants (POPs) are a class of chemicals synthesized for human production or generated alongside human life and industrial production. Because they are difficult to degrade, highly toxic and capable of long-range transport, their production, use and release pose a serious threat to public health and to the ecosystem, and they have become environmental pollutants of global concern.


UV-328
UV-328 is one of the representative substances in the ultraviolet stabilizer family.

They are commonly added to plastic packaging to prevent harmful ultraviolet radiation, and are also added to products to reduce fading and inhibit corrosion. They may be released into the environment during production, use and disposal.

UV-328 is widely present in products such as coatings, personal care products, toys and hair accessories. Besides long-range transport through the sale and use of products, UV-328 also spreads through aerosol particles, migratory species such as seabirds, and long-range atmospheric transport.
UV-328 has been shown to be toxic to mammals; repeated exposure causes specific organ toxicity to the liver and kidneys.

Dechlorane Plus

Dechlorane Plus is a hazardous flame retardant chemical with highly persistent toxicity and bioaccumulative properties. In simple terms, it is a plastic additive with adverse effects on the liver, the endocrine system and neurodevelopment.

Dechlorane Plus can be transported long distances through air and seawater, and can also reach remote areas through migratory species and the ocean transport of plastic debris.
Dechlorane Plus is frequently detected in baby food (formula milk powder, cereals and purees) produced in China, and very high concentrations have also been found in other formula food samples.
Like UV-328, Dechlorane Plus can migrate long distances in the environment and may harm human health and the environment. The most effective way to avoid these risks is a complete ban on production, sale and use.


Methoxychlor
Methoxychlor controls a wide range of pests, including flies, mosquito larvae and cockroaches.

However, as understanding of its environmental and ecological effects has grown, methoxychlor has been shown to be harmful to the environment and human health.

On 27 October 2017, the International Agency for Research on Cancer of the World Health Organization published a preliminary list of carcinogens, in which methoxychlor is included in group 3.

Overall, the decision of the eleventh Conference of the Parties to list UV-328, Dechlorane Plus and methoxychlor under the Convention is important progress, because these toxic chemicals pose a potential threat to people and the environment. Long-term exposure to these substances has been shown to have adverse health effects, in particular harming the neurodevelopment and endocrine system of children.
Countries around the world had worked towards this decision for more than 20 years. The adoption of the compliance mechanism for persistent organic pollutants is therefore a historic step with far-reaching implications for achieving the objectives of the Convention and advancing global sustainable development.