What additionality means for plastic credits
Additionality is the test that asks a simple question: would this plastic have been collected or recycled anyway? A plastic credit is only meaningful if the answer is no. If a collection programme was already running profitably, or was already required by law, then the credit sold from it represents no extra benefit. The buyer pays, the claim is made, and the amount of plastic kept out of the environment does not change.
The concept comes from the voluntary carbon market, where it has been debated for many years, and plastic credit standards have adopted a version of it. Understanding how it works helps buyers ask better questions and helps developers design projects that stand up to scrutiny.
The baseline: what would have happened without the project
Additionality cannot be judged without a baseline, a description of the most likely situation if the project did not exist. For a plastic project, the baseline usually covers three things:
- Existing collection: how much plastic was already being gathered in the project area, by municipal services, informal collectors or private operators.
- Existing demand: whether recyclers or processors were already buying this material at a price that made collection viable.
- Legal requirements: whether regulation, including extended producer responsibility schemes, already obliged someone to collect or treat the material.
The project is then measured against that baseline. Only plastic collected or processed over and above it can fairly be turned into credits. A weak baseline, for example one that ignores informal collectors already active in the area, can quietly inflate the number of credits a project issues.
Three common ways additionality is tested
Financial additionality
The project demonstrates that it could not operate without the revenue from credits. If the plastic has enough market value to pay for its own collection, credit income is a bonus rather than the reason the activity happens. Developers typically show this with a cost and revenue model that reviewers can examine.
Regulatory additionality
The activity must go beyond what the law already requires. Where producer responsibility rules oblige companies to fund collection and recycling, plastic recovered to meet those obligations generally cannot also be sold as a credit. This is one reason the relationship between credits and EPR is closely watched.
Common practice
The project is compared with what is normal in the region. Introducing collection in an area with no existing system is clearly different from adding a small payment to a mature recycling market. The more common the activity already is, the harder it is to argue the credit changed anything.
Where additionality gets difficult in plastics
Plastic markets are local, informal and fluid, which makes baselines harder to draw than in many other sectors. The value of waste plastic moves with oil prices, polymer type and local demand, so an activity that needed support one year may be profitable the next. Informal waste pickers often supply a large share of recovered material but are poorly recorded, which makes it easy to misjudge what was happening before a project began.
There is also a displacement risk. If a project simply pays collectors to redirect plastic that another recycler was already buying, the total amount recovered may not rise at all. Good projects look for materials with low value, such as thin films and multilayer sachets, or for geographies with no existing system, where credit income truly changes behaviour.
Questions buyers can ask
- How does the project document its baseline, and who reviewed it?
- Was the collected material already being sold to recyclers before the project started?
- Does any law or EPR scheme already require this collection?
- Would the project continue if credit sales stopped, and what does the financial model show?
- How does the project guard against displacing material from existing recyclers?
Clear, specific answers are a good sign. Vague references to impact without a described baseline are a reason to look more closely, or to use the due diligence checklist elsewhere in this knowledge bank.
Frequently asked questions
Is additionality the same as permanence or leakage?
No. Additionality asks whether the project caused extra benefit. Leakage asks whether the activity simply moved the problem elsewhere, and permanence concerns whether the benefit lasts. They are related quality tests, and a credible project should address all three.
Does a higher price mean a credit is more additional?
Not necessarily. Price reflects many things, including geography, material type and co-benefits. Additionality has to be judged from the project documentation, not inferred from the price.
Who checks additionality?
The standard sets the rules, the developer documents the case, and an independent validation and verification body reviews it. Buyers can read the public project documents on the registry to see the reasoning for themselves.
Can a project be additional in one year and not the next?
Yes, because market conditions change. This is why standards require projects to be reassessed at renewal and why buyers should look at the current version of the documentation.
The takeaway
Additionality is the question that connects a credit to a real-world outcome. A buyer who understands baselines and can read how a project argues its case is far better placed to choose credits that represent genuine extra plastic recovery, and to describe that purchase honestly.
About the author
Plastic Units editorial team
Editorial team
The Plastic Units editorial team writes and maintains the Knowledge Bank and news on the plastic credits market, recycling economics and plastic policy.