What is residual waste matching?
Residual waste is the material that leaves your facilities as waste rather than ending up in a product — things like production scrap, packaging waste, process sludge, or wastewater. Treating this waste has an environmental impact, through landfill, incineration, recycling, or other treatment routes.
To account for this, each residual waste item in Root is matched to a single impact reference that represents how the waste is treated at end-of-life. This is what we call residual waste matching.
Residual waste only needs one match. Unlike consumables, which need two (one for production and one for end-of-life), a waste stream is already an output of your process, so there is no production phase to account for — only its treatment.
Where residual waste comes from
Residual waste is generated at your facilities during operations. Each waste item is linked to one or more facilities, and the relations are tracked per reporting year. You can see which facilities a waste item relates to, and in which years, on its detail page.
The Residual Waste page
Use the year filter to focus on a specific reporting year, or toggle Year unrelated to see all items. The + Add button lets you add a new waste item. The counters at the top right show how many items are Total, Complete, and Incomplete.
Explanation of columns
Name: Name of the residual waste item (e.g. Paper, Metal scrap).
Match: The impact reference linked to the waste, e.g. an Ecoinvent waste dataset such as market for waste packaging paper.
Impact: The carbon and environmental impact of the matched reference.
Facility relations: The number of facilities that generate this waste.
Status: Whether the item has been fully matched.
How to match your residual waste
Step 1: Add your residual waste items
Add waste items with the + Add button or through a data upload. Each item starts with a name and no impact data.
Step 2: Review your residual waste
Each item shows its current status:
Complete — An impact reference is assigned and any required unit conversion is in place.
Incomplete — The impact reference is missing, or a required unit conversion is missing.
Step 3: Assign the impact reference
Click on a waste item name to open its detail page.
Click the Edit button in the Impact section to add an impact reference.
Use the database tabs to select the reference that matches the waste (e.g. market for waste packaging paper). See an explanation of how to choose an impact reference here.
The reference is now linked and the resulting impact is automatically calculated.
When choosing a reference, match the waste on both the type of waste (its material and form, e.g. waste packaging paper vs. metal scrap) and the geography where it is treated. Treatment methods and their impacts differ significantly by region, so the closer the dataset reflects how and where the waste is actually handled, the more representative the result.
Step 4: Set unit conversions (if needed)
The Impact section shows the reference's basis (e.g. 1 kg impact). If the unit recorded for the waste differs from the dataset's unit, you'll need to provide a conversion factor in the Unit conversion section. Common conversions (like grams to kilograms) are handled automatically — you only need to set a factor when Root can't convert between the units on its own.
Tips
Match the waste type, then the geography. Pick the Ecoinvent waste dataset that corresponds to your waste material, then choose the version closest to where the waste is actually treated.
Focus on your largest waste streams first. The items with the highest volumes will have the largest effect on your results.
Use the year filter to focus your work. Filter by reporting year to see only the waste items relevant to a specific period.
Check your units. If a waste item stays Incomplete after matching, it may be missing a unit conversion.