Stretch film CO₂e: how to estimate it, and how to cut it
The simple estimate
For a customer’s stretch film, the estimate has two parts:
- Film per year. Grams of film per pallet multiplied by the number of pallets a year.
- The factor. An emission factor in kilograms of CO₂e per kilogram of film.
Film per year in kilos, multiplied by the factor, gives the estimated CO₂e of the film. When a customer moves to less film per pallet, the kilos saved multiplied by the same factor gives the estimated reduction.
Example: a pallet used 270 g of film before and 230 g after. At 650 pallets a day and 220 working days, that is 5,720 kg of film saved a year. With a factor of 2.97 kg CO₂e per kg of film, the estimated reduction is about 17.0 t CO₂e a year. This is an example, not a promise: real numbers depend on the customer’s pallets and film.
What the factor covers, and why it varies
An emission factor for film usually covers making the raw material and producing the film, up to the point where it leaves the factory or reaches the buyer. This is often called cradle-to-gate. It varies with:
- the resin: LLDPE and metallocene grades have different footprints,
- recycled content: recycled polyethylene has a much lower footprint than virgin resin,
- the production site: its energy mix and efficiency,
- the scope: whether only the resin is counted, or also forming the film, transport and end of life.
A factor for resin alone is lower than one that includes turning the resin into film. That is why the film producer’s own figure is the best one to use, and why any report should state which factor it used.
Always ask the film producer
Before using a generic value, ask the producer of each film for its CO₂e figure. Ask for:
- kg CO₂e per kg of film, for the exact film, not the product family,
- what it covers, for example cradle-to-gate, and whether forming the film is included,
- the recycled content the figure is based on,
- the source, such as an EPD with its number and year, so the figure can be checked.
When the producer has a figure, enter it on that film, and the report prints it with its source.
Reference values
When the producer has no figure, a published generic value is the next best choice. The UK government’s greenhouse gas conversion factors for 2025 (material use, scope 3) give these values for polyethylene, including forming:
| Material | kg CO₂e per kg |
|---|---|
| LDPE and LLDPE, new material | 2.97 |
| LDPE and LLDPE, recycled (closed loop) | 1.10 |
| Average plastic film, new material | 2.92 |
The same example with different factors shows how much the choice matters. 5,720 kg of film saved is about 17.0 t CO₂e with the factor for new LDPE and LLDPE, and about 6.3 t with the factor for recycled material. The film saving is the same in both cases. Only the factor changes.
Palletseal uses 2.97 kg CO₂e per kg as its default, the generic value for new LDPE and LLDPE above. For a film with recycled content, or when the producer has its own figure, change the factor for that film.
Why less film is the fastest cut
The estimate scales directly with weight. Every kilo of film that is not used removes its full factor from the total. The biggest reductions usually come from:
- running the film at its rated pre-stretch instead of far below it (see the right pre-stretch),
- choosing the right film for the load, often thinner and stronger (see cast vs blown),
- fixing the wrapping pattern, so wraps go where the load needs them.
The condition is always the same: the load must still hold. A film saving that leads to damaged goods is not a saving, for the customer or for the climate. Check it with a tilt test and containment force on the same load.
How to report it honestly
- Label it as an estimate, not a certified footprint.
- Print the factor and where it comes from.
- Use the same factor for every film in a comparison, unless a producer has its own documented figure.
- Keep film and cost figures separate from the CO₂e figure: film and cost are calculated from measurements, CO₂e is an estimate.
Palletseal prints the estimated CO₂e with the factor and its source in every report, next to the film and cost saving and the load stability results.
Source for the reference values: UK Department for Energy Security and Net Zero, Greenhouse gas reporting: conversion factors 2025, condensed set, sheet “Material use”.
Questions we often get
How is the CO₂e of stretch film calculated?
Kilos of film used per year multiplied by an emission factor in kg CO₂e per kg of film. The saving is the kilos of film saved multiplied by the same factor.
Which factor should I use?
Always ask the film producer first. Its own figure, ideally from an environmental product declaration (EPD), reflects the actual film. Only when the producer has no figure, use a published generic value for polyethylene film. Always state which factor was used and where it comes from.
Which factor does Palletseal use?
A default of 2.97 kg CO₂e per kg of film, the UK government's generic value for new LDPE and LLDPE in its greenhouse gas conversion factors for 2025. It can be changed per film, for example to the producer's EPD value, and the factor used is printed in the report with its source.
Is this a certified carbon footprint?
No. It is an estimate based on the film used or saved and a factor. A certified carbon footprint or life-cycle assessment follows a defined standard and covers more of the product's life.
Does recycled content lower the CO₂e?
Yes, usually by a lot. The UK government's factor for recycled LDPE and LLDPE is about 1.10 kg CO₂e per kg, against 2.97 for new material. Use a factor that reflects the actual film if you want to show that difference.
