Answer
The Stockholm Convention on Persistent Organic Pollutants (POPs) is a global environmental treaty intended to protect human health and the environment from Persistent Organic Pollutants.
It was adopted in Stockholm, Sweden, on 22 May 2001 and entered into force on 17 May 2004.
What are POPs?POPs are chemicals that:
- Persist in the environment for a long time.
- Bioaccumulate in humans and animals.
- Biomagnify through the food chain.
- Are toxic to humans and wildlife.
- Can undergo long-range environmental transport, so pollution can affect countries far from the original source.
Typical examples include PCBs, DDT, dioxins and furans.
Main objectiveThe Convention requires Parties to eliminate, restrict or reduce the release of POPs.
The chemicals are principally dealt with through three annexes:
| Annex | Requirement | Easy memory |
|---|---|---|
| Annex A | Elimination of listed POPs, subject to specified exemptions | A = Abolish |
| Annex B | Restriction of production/use | B = Bound/Restricted |
| Annex C | Reduce and, where feasible, ultimately eliminate unintentional production/releases | C = Control releases |
Annex A – Elimination includes many pesticides and industrial chemicals such as PCBs, PFOA, PFHxS, DecaBDE, Dechlorane Plus and UV-328.
Annex B – Restriction includes:
- DDT
- PFOS, its salts and PFOSF
Annex C – Unintentional releases includes substances such as:
- Dioxins (PCDD)
- Furans (PCDF)
- PCBs
- Hexachlorobenzene.
Countries are broadly required to:
- Prohibit/eliminate production and use of Annex A chemicals, subject to permitted exemptions.
- Restrict Annex B chemicals.
- Reduce unintentional releases under Annex C.
- Ensure environmentally sound management of POPs-containing wastes.
- Develop a National Implementation Plan (NIP).
- Prevent introduction of new chemicals with POP-like characteristics.
- Promote safer alternatives and best environmental practices.
At COP-12, held from 28 April to 9 May 2025, three additional chemicals/groups were adopted for listing in Annex A:
- Chlorpyrifos
- Medium-chain chlorinated paraffins (MCCPs)
- Long-chain perfluorocarboxylic acids (LC-PFCAs), their salts and related compounds
For a marine engineer, the Stockholm Convention is particularly relevant to:
- PCBs historically present in electrical equipment/transformers.
- Certain flame retardants used in materials and equipment.
- POP-containing waste generated during repair, recycling or disposal.
- Ship recycling/IHM, because hazardous substances must be identified and managed appropriately.
- Incineration and combustion, because poor combustion can contribute to formation/release of dioxins and furans.
Stockholm Convention is not an IMO convention.
It is a global chemicals/environmental convention administered through the UNEP framework, whereas ship-source pollution requirements are mainly dealt with through instruments such as MARPOL.