The Sustainability of Tack-Back Programs – https://re-advance.com/science-and-sustianability/

Every sustainability enthusiast wants take-back programs to make sense.

However, to truly assess the sustainability of take-back programs, we would need to know:

The distance between the research facility and recycling plant
The type and frequency of transport
The item properties (type and amount of waste collected)
The recycling method (mechanism, recycling rates, and how the recycled material is used)

Unfortunately, not a single company has openly shared a footprint or life cycle analysis, hence, we have to rely on assumptions and estimates.

PS: A TL;DR Summary is to be found at the bottom of the page : )

Nevertheless, let’s look at some number to get a feel for the order of magnitude we’re talking about here:

Overall Plastic Impact

If we consider the entire life cycle of plastics that means from production to End-of-Life we arrive at the following numbers (I listed the journals name as links to see which are papers and which are other sources):

CISL: 5000 CO₂/kg
Material Economics et al., Industrial Transformation 2050: Pathways to Net-Zero Emissions from EU Heavy Industry. 2019. University of Cambridge Institute for Sustainability Leadership (CISL). https://materialeconomics.com/publications/industrial-transformation-2050
Nature: 4200 g CO₂e/kg
Zheng, J. et al., Strategies to reduce the global carbon footprint of plastics. 2019. Nature Climate Change, 9, 374–378. doi:10.1038/s41558-019-0459-z

That means, 4-5kg CO2e per kilogram plastic is the maximal amount of carbon we could save after all by reducing our use. If we were to reuse our items, we would at least save 1/x with x being the times we reuse the item.

=4000-5000gCO2/kg plastic waste

Virgin Plastic Production:

One key point in our discussion will be the difference in emission when creating new (virgin) plastics from crude oil or natural gas versus recycling the same item.

JRC Techincal Report: 1547g CO2/kg
Technical Report: Tonini, D. et al., Environmental effects of plastic waste recycling. 2021. JRC Technical Report, Joint Research Centre, European Commission. doi:10.2760/22311

CISL: 2300 CO₂/kg
Material Economics et al., Industrial Transformation 2050: Pathways to Net-Zero Emissions from EU Heavy Industry. 2019. University of Cambridge Institute for Sustainability Leadership (CISL). https://materialeconomics.com/publications/industrial-transformation-2050

Wiley: 2500-3000g/kg

Bataineh, K. M. et al., Life-cycle assessment of recycling postconsumer high-density polyethylene and polyethylene terephthalate. 2020. Advances in Civil Engineering, Volume 2020, Article ID 8905431, 15 pages. doi:10.1155/2020/8905431

= 1500-3000gCO2e/kg plastic waste

End-of-Life Impacts

Now, let’s zoom in on the emissions released once plastic items are thrown away.

We will not assume that plastic items are autoclaved after use because contaminated items cannot be included in take back programs and even if such a step is included for “safety reasons” I would add the same amount to each scenario.

Still, there are a few ways to treat plastics after they have been discarded:

Landfilling plastics

RSC: ~253 g/kg (due to methane release)
Eriksson, O. et al., Plastic waste as a fuel – CO₂-neutral or not? 2009. Energy & Environmental Science, Issue 9. doi:10.1039/B908135F

JRC Techincal Report: 400-800g CO2/kg
Technical Report: Tonini, D. et al., Environmental effects of plastic waste recycling. 2021. JRC Technical Report, Joint Research Centre, European Commission. doi:10.2760/22311

If you are surprised by this number, remember that we only look at climate change impact, i.e., CO2e, whereas for landfilling, microplastics and leaching additives are bigger concerns.

=250-800gCO2/kg plastic waste

Incineration

RSC: 500–4500 g/kg
Eriksson, O. et al., Plastic waste as a fuel – CO₂-neutral or not? 2009. Energy & Environmental Science, Issue 9. doi:10.1039/B908135F

IPCC: 2697 g/kg of plastic waste
2006 IPCC Guidelines for National Greenhouse Gas Inventories

Polystyrene (PS) and PE (around 3 kg/kg plastics) and lower for e.g. PP and PUR (around 2.5 kg/kg plastics). For the purpose of this work, 2.7 kg CO2/kg plastics have been used for all incinerated end of life plastics

JRC Techincal Report: 1391g CO2/kg

Technical Report: Tonini, D. et al., Environmental effects of plastic waste recycling. 2021. JRC Technical Report, Joint Research Centre, European Commission. doi:10.2760/22311

ScienceDirect: 780g/kg with energy recovery
van der Hulst, M. K. et al., Greenhouse gas benefits from direct chemical recycling of mixed plastic waste. 2022. Resources, Conservation and Recycling, Volume 186, Article 106582. doi:10.1016/j.resconrec.2022.106582

Commonly, one differentiates incineration and energy recovery. While energy recovery refers to converting waste into usable energy (like electricity or heat), often through combustion, incineration basically means pure burning of waste, not capturing that energy. Obviously, the more energy can be recovered for other applications, the lower the carbon release impact as the emissions that would be created to generate this energy is deducted.

Some even suggest negative impacts for energy recovery because under ideal energy recovery conditions and when using biogenic carbon (bioplastics) one can argue that one gets energy from carbon that was fixed by plants before. However, this is beyond our current discussion (see our previous discussion: https://readvance.ck.page/posts/biogenic-carbon.

=700-4500gCO2/kg plastic waste

Impact of mechanical recycling

We have to remember that recycling takes energy too – we have sort the plastics, clean them and turn them into pellets/the new product. That means running the machines and sometimes heat the plastics.

ScienceDirect: 4.4 kg CO₂/kg -> note that this the impact of open-loop recycling (thus, the high number)
Schwarz, A. E. et al., Plastic recycling in a circular economy: Determining environmental performance through an LCA matrix model approach. 2021. Waste Management, Volume 121, Pages 331–342. doi:10.1016/j.wasman.2020.12.020

JRC Techincal Report: 400-800g CO2/kg
Schwarz, A. E. et al., Plastic recycling in a circular economy: Determining environmental performance through an LCA matrix model approach. 2021. Waste Management, Volume 121, Pages 331–342. doi:10.1016/j.wasman.2020.12.020

((Wiley: <300 g/kg (Review) – but all values very low
Vollmer, I. et al., Beyond mechanical recycling: Giving new life to plastic waste. 2020. Angewandte Chemie International Edition, Volume 59, Pages 15402–15423. doi:10.1002/anie.201915651))

Wiley: 600-700g/kg – cut-off (with system expansion data there too)

Elsevier: 111g/kg
Sharma, R. et al., Gate to gate life cycle assessment of greenhouse gas emissions and acidification potential in plastic recycling technologies in Nepal. 2025. Results in Engineering, Volume 26, Article 105367. doi:10.1016/j.rineng.2025.105367

MDPI: 150g/kg
Tinz, J. et al., Carbon footprint of mechanical recycling of post-industrial plastic waste: Study of ABS, PA66GF30, PC and POM regrinds. 2023. Waste, Volume 1, Pages 127–139. doi:10.3390/waste1010010

=100-800gCO2e/kg plastic waste

Important Note:

Plastic recycling is limited – Eventually, plastics will still be incinerated or landfilled. See the following two publications if you want to know more:

Schyns, Z. O. G. et al., Mechanical recycling of packaging plastics: A review. 2020. Macromolecular Rapid Communications, First published: 30 September 2020. doi:10.1002/marc.202000415

Eriksen, M. K. et al., Closing the loop for PET, PE and PP waste from households: Influence of material properties and product design for plastic recycling. 2019. Waste Management, Volume 96, Pages 75–85. doi:10.1016/j.wasman.2019.07.005

That means, in most cases, one would simply prolong the inevitable.
Even when downcycled into construction materials (which may last 40+ years), end-of-life recycling is unlikely.

That means that from a life-cycle perspective, we would theoretically need to include some amount or fraction of incineration or landfilling impacts eventually.

Truck emissions

Assuming the lab and the incinerator or recycling facility are similarly distant, truck emissions may balance out. However, if take-back programs require additional trips with half-empty trucks (since they only collect waste from a specific manufacturer), emissions can add up.
• Trucks emit ~50–400g CO₂ per ton per km
• vehicle empty weight: 2–15 tons
• Max carrying capacity: ~40 tons

The difficulty here is that we will have to make a large number of assumptions with dramatic impacts when we try to estimate transportation-related emissions. Initially, especially in countries like the US with large waterway transport opportunities, we would probably see a lot of sea transport. Still, with reference to truck travel, it is unclear what size of truck we should assume and what final weight. Plastic is relatively light, so even a full truck will not reach 40 tons unless the plastic is compressed beforehand.

Moreover, it is almost impossible to estimate travel distances because waste management remains largely a black box. There is little information about where recycling centers are located and how waste is treated — even in countries like Germany. Without insider information, it’s nearly impossible to estimate concrete distances. Even identifying recycling centers or landfills is challenging — possibly not least because of the shady history the waste industry has gone through. Therefore, we have to live with a wide range of potential values in our calculations.

Providing Perspective

Many of the numbers above are mostly taken from life-cycle-based approaches. This means there are important nuances:

gCO₂e/kg only measures climate change impact.
Microplastics and additives can harm environments — whether soil or air. Contaminated water from washing steps or the use of chemicals can cause marine biotoxicity and acidification. Incineration may release dioxins, which are toxic as well. Including those impacts would make the discussion lengthy and overly complex — not only are data even scarcer, but they vary significantly, and it’s impossible to judge how much acidification potential is equivalent to, say, 20 grams of additional carbon and 0.5 grams of additional nitrous oxide.
LCAs have different system boundaries.
We cannot exactly quantify the impact of manufacturing the machines used to burn or recycle plastics. These are often left out, and we must assume that building an incinerator is as impactful as building a recycling line. System boundaries matter greatly (known in LCA terms as “cut-off” or “system expansion”) — for example, whether the initial production of plastics is entirely excluded or partially included in the recycling life cycle assessment. Transport distances also fall under these boundaries.
Impact is always measured over a time scale.
Many LCAs use a 100-year time horizon. But there’s no good reason why 50- or 200-year impacts should be less relevant. In reality, our estimates probably mix 50- and 100-year-focused numbers.
“Plastics” is not one material.
As you’ve seen, we’ve been speaking broadly about “plastics.” But numbers vary not only between well-known types like PP, PE, and PET, but also for multilayered plastics.
Conversion factors are heavily location-dependent.
For example, when calculating the impact of recycling plastic, we need energy to power the machines — typically 250–500 kWh per ton. Even if we ignore that heating is often done with natural gas, the CO₂e output depends on where the energy comes from. Countries with a lot of hydroelectricity fare better than those reliant on coal. While Germany might use a factor of 200–300 g/kWh, some papers use 67 g/kWh for Nepal — a surprisingly low figure, yet still peer-reviewed. This can cause final numbers to vary by a factor of 3–4.

Impact Calculation

Let us try to calculate how sustainable take-back programs can be.

Here is an Excel sheet, where you can play with the numbers and the amount of plastic waste returned – 1 kg, 5 kg, 100 kg, or however much you like.

The catch: while transport emissions may seem small if calculated for only moving the plastic itself, once we consider that a vehicle weighing several tons carries would need to drive additional kilometers for a limited amount of plastic, those emissions become more noticeable.

How Companies Handle That

Most companies use already established mailing routes, as they provide shipping labels. It seems likely that the boxes are then collected at mail stations and transported to specific recycling plants.

The issue arises from the fact that when using a take-back program, providers might only collaborate with a handful of recycling partners, potentially located farther away. Or maybe not — we simply don’t know.

Of course, it also seems likely that most companies work with subcontractors. But since those arrangements are often kept confidential, even the providers themselves might not know details about transport or other environmental impacts.

What That Means

The more plastic waste you return, the more favorable the carbon savings become.

Still, there is a major problem:
No matter how we calculate it, the key limitation is that we basically know nothing about most take-back programs.

Travel distances can easily range from 5 to over 1,000 km if collection, sorting, recycling, and manufacturing facilities are in different locations.
To properly calculate carbon footprints, we would need to know:

Does the take-back provider have a dedicated vehicle fleet, or do they subcontract transport via FedEx or mail?
What types of vehicles are used?
Which sorting and recycling facilities do they work with?

If you assume a 3.5-ton transport vehicle that carries 10 kg of waste, you end up saving 11 kg of CO₂e if the additional drive is 5 km, but you emit 10 kg extra if it is 20 km.

If we assume true recycling for three cycles, we save 82.5 kg CO₂e for 5 km and break even at around 62.5 km.

However, additional travel can easily exceed 100 km.

The Final Verdict

In the end, we cannot clearly say whether take-back programs are inherently sustainable.

If you want to decide whether a take-back progams makes sense for you, you need to know

The amount of plastic waste you will return
The mode of and(average) transport distances
How your waste is treated (how often it is recycled or whether it is actually downcycled)

The key issue: delivery and distance must be assessed on a case-by-case basis.

Still, a major drawback is that most “recycling” programs actually downcycle. That means they produce lower-quality products such as playground floormats or construction filler materials.

It’s also debatable whether there’s enough demand for recycled plastic — even if capacity exists. Nevertheless, one could argue that downcycling still delays incineration or landfilling, which might buy us precious time to reduce emissions and develop better technologies.

If we assume that take-back programs don’t require more travel than conventional waste treatment, they offer an advantage — but only if they truly recycle. Since virgin plastic production is more energy-intensive than mechanical recycling, we can save emissions with every cycle. However, recycling isn’t infinite. Eventually, plastics degrade and must be discarded.

Take-back programs do offer one big benefit: they help ensure clean waste streams made of just one plastic type. This is crucial because separating and identifying plastics can be energy-intensive — and sometimes even impossible. Take-back systems also incentivize manufacturers to design items using a single material, making future recycling easier.

In essence, take-back programs can cause harm in the wrong context but offer real benefits in the right one. Every lab should only participate if their service provider can clearly explain how the waste is transported and treated.

Since take-back programs will always emit emissions, the only real solution remains reduction. Therefore:
Reduction first, reuse second, and recycling before downcycling.

TL;DR:

We have little data, as no take-back program has published LCAs or transparent documentation.
Most take-back programs downcycle rather than truly recycle.
Even real recycling uses energy, has environmental impacts, and can’t be done indefinitely.
An often overlooked factor is how far the waste travels.
These factors must be disclosed by the provider to assess the sustainability of the program.
Reduction is most sustainable. Reuse is more sustainable than take-backs, as sorting, washing, grinding, and remanufacturing require energy.
If recycling is done properly, take-back programs can avoid virgin plastic use and reduce end-of-life impacts — but only up to a point.
Still, take-back programs can save a lot of carbon when done properly.