Station 6 of 6 Inspect, repair, retire
Bread Tray Sustainability: Reusable vs. Single-Use Packaging in Bakeries
Contents: 8 sections
- What goes into a tray program’s carbon and waste figure?
- How do you turn those inputs into a per-trip figure?
- What does the figure include, and what does it leave out?
- Why can’t you use a published reusable-versus-single-use percentage?
- How do trays show up in a corporate greenhouse gas report?
- What is your program’s waste figure?
- What data should you collect before the first report?
- What should your first report say?
For a bakery that already runs reusable trays, the figure to report is the program’s own, and it comes from four inputs you can measure: the emissions of making the trays, how many trips a tray makes before it is retired or lost, the energy and water the washer uses per tray, and how empties travel back. Published comparisons cannot stand in for them. Two reviewed studies of produce crates reached different conclusions, and the one whose full report was checked for this page names reuse, breakage and losses, and transport distance among the ways to lower the reusable container’s impact.
What goes into a tray program’s carbon and waste figure?
| Input | How to measure it | Where it sits in a GHG inventory |
|---|---|---|
| Making the trays | Trays bought, their weight, and the supplier's cradle-to-gate emissions figure per tray | Scope 3, category 2 (capital goods) or category 1, following your accounting |
| Washing | Washer electricity, fuel and water for a period, divided by trays washed in that period | Scope 2 for purchased electricity; scope 1 for fuel burned in your own washer or boiler |
| Return transport | How empties come back, and on whose trucks | Scope 1 if your own trucks carry them |
| Trays leaving the fleet | Trays retired and trays lost per year, times tray weight | Retired trays you dispose of: scope 3, category 5 (waste generated in operations) |
Sources for the table: GHG Protocol scope 3 categories and capital goods guidance, and EPA scope 1 and scope 2 definitions, cited in the reporting section below.
How do you turn those inputs into a per-trip figure?
Add three parts:
Per-trip figure = (manufacturing emissions of one tray ÷ trips per tray) + washing per trip + return transport per trip
The first part is where loss shows up. Trips per tray is not the design life the maker quotes; it is what your fleet achieves. The quickest estimate is a management proxy, not a life cycle measurement: with a fleet that stays about the same size, divide the tray trips you ran in a year by the trays that left the fleet that year, retired and lost together.
For example, a fleet that runs 1,200,000 tray trips a year and loses or retires 6,000 trays gets 200 trips per tray, so each trip carries 1/200 of a tray’s manufacturing emissions. If losses rise until 12,000 trays leave in a year, trips per tray fall to 100 and the manufacturing share of every trip doubles. The proxy drifts when the fleet is not steady. A growing fleet, a fleet bought mostly in one year, or a year with an unusual wave of retirements will each push it off, and it blends trays lost early with trays retired late. If your trays carry IDs, or you know which purchase lot each retired tray came from, count trips per tray for each lot instead: that is the tray’s actual life, not an estimate of it. Until then, report the proxy as a proxy, and in a year you are growing the fleet, use the trays that left, not the trays you bought, or the new trays will read as losses. How to count losses by route is set out in counting outbound against returned trays by route.
Washing per trip comes from meter readings, not from the washer’s brochure: the washer’s electricity, fuel and water over a month, divided by the trays it washed that month. What a washer’s stages use, and how to size one, is in the stages and capacity of an automated tray washer.
Return transport is the input you need a written rule for. If empties ride back on the same delivery trucks, that fuel is already in your inventory, and a per-trip figure needs a stated way of assigning part of it to the trays, such as by weight or by share of space. Write the rule down next to the figure, because a different rule gives a different number. That is enough for an internal figure. For a figure you publish or use to compare packaging systems, have the method built or reviewed against the life cycle assessment standards both studies below say they followed, ISO 14040 and ISO 14044, rather than relying on a rule of your own.
What does the figure include, and what does it leave out?
Write the boundary down before the number, because two programs with the same trays can report very different figures by drawing it differently. The boundary this page describes:
| Included | Left out, unless you add it | |
|---|---|---|
| Life stages | Making the trays; washing; the empty return leg; retired trays leaving the program | The bread and its bags; the trays' share of the loaded outbound trip; store handling |
| Equipment | Trays | Dollies, racks, lids and the washer itself |
| Assumptions | A fleet of steady size, for the trips-per-tray proxy; your written transport rule; the supplier's cradle-to-gate figure and its method | Changes in loss or breakage you have not yet measured |
Sources for the table: this guide’s suggested boundary for an internal figure, not a published standard. If you compare packaging systems in public, the boundary and assumptions have to follow the method you claim, as the studies below illustrate.
If you change the boundary from one year to the next, restate the previous year on the new boundary or say plainly that the two years are not comparable.
Why can’t you use a published reusable-versus-single-use percentage?
Because the studies disagree, and their results rest on assumptions about the same inputs your own figure needs.
Comparative studies (checked September 26, 2026). Both studies compare reusable plastic containers with corrugated boxes for fresh produce, not bread trays, and each comes from one side of the comparison.
- Released by IFCO, which supplies reusable plastic containers, 2017. IFCO reported that its containers “produce 31% less global warming potential (carbon dioxide equivalents)” than display-ready corrugated boxes, in a study that “was conducted by Franklin Associates (Franklin), a nationally-recognized life cycle assessment and solid waste management consulting firm, in accordance with ISO standards 14040 and 14044” (IFCO, March 16, 2017).
- Commissioned by the Corrugated Packaging Alliance, April 24, 2025. The study, by Anthesis, states: “Results from the current study do not indicate that either system is clearly a superior overall environmental performer.” Its reusable-container baseline “is predicated on 24 uses, with an aggregate break and loss rate of 5%,” and it states that “Impacts from the RPC system can be reduced by increasing reuse, incorporating recycled content, minimizing breakage and losses, and reducing transport distances” (<a href="https://www.fibrebox.org/assets/2025/10/CPA2025-CormparativeLCAFullStudy.pdf”>Corrugated Packaging Alliance, Anthesis, 2025).
A bread tray fleet has its own trips, loss rate, washer and routes. Quoting either study’s result in your report tells the reader about produce crates under that study’s assumptions, not about your trays.
How do trays show up in a corporate greenhouse gas report?
Differently from the per-trip figure, and the difference matters when both appear in one report.
The GHG Protocol’s scope 3 guidance defines capital goods as “final products that have an extended life and are used by the company to manufacture a product; provide a service; or sell, store, and deliver merchandise.” It adds: “Companies should follow their own financial accounting procedures to determine whether to account for a purchased product as a capital good in this category or as a purchased good or service in category 1.” For capital goods, it says companies “should not depreciate, discount, or amortize the emissions from the production of capital goods over time,” and should instead account for “the total cradle-to-gate emissions of purchased capital goods in the year of acquisition” (<a href="https://ghgprotocol.org/sites/default/files/standards/Scope3CalculationGuidance_0.pdf”>GHG Protocol, Technical Guidance for Calculating Scope 3 Emissions, 2013).
So in the corporate inventory, a year in which you buy a new fleet carries all of its manufacturing emissions, and the years after carry none. The per-trip figure spreads the same emissions over trips. Both are correct for their purpose; label which one a number is, and do not add one to the other.
For washing and your own trucks, EPA describes scope 1 as direct emissions from sources the organization owns or controls, including fuel burned in boilers, furnaces and vehicles, and scope 2 as indirect emissions from purchased electricity, steam, heat or cooling (EPA, Scope 1 and Scope 2 Inventory Guidance). To turn fuel and electricity into emissions, EPA’s GHG Emission Factors Hub provides “a regularly updated and easy-to-use set of default emission factors for organizational greenhouse gas reporting” (EPA, GHG Emission Factors Hub).
What is your program’s waste figure?
The plastic that leaves the program each year: trays retired plus trays lost, times the weight of one tray. Split it by what you know happened to it:
- Returned to a recycler or a maker’s take-back program, with a receipt or weight ticket.
- Disposed of as waste, with the hauler’s record.
- Lost, with no known fate. Do not count these as recycled or as landfilled; report them as lost.
The loss line is the one to watch, because it moves both figures at once: every lost tray adds plastic with no known fate and cuts the trips that carry its manufacturing emissions. What recycled content in a new tray means under FDA’s guidance, and what a take-back offer covers, is in recycled content, take-back and what FDA allows.
What data should you collect before the first report?
- Trays bought, by model and weight, and the supplier’s cradle-to-gate emissions figure for each model. Ask for it in writing, with the method and data source behind it. Some suppliers offer an assessment; ORBIS, for example, says it “applies data-driven analysis to help customers reduce their overall environmental impact in terms of greenhouse gas emissions, solid waste and energy usage” (ORBIS, Packaging Life-Cycle Assessment).
- Trays retired and trays lost per year, counted separately.
- Washer meter readings for electricity, fuel and water, with the trays washed in the same period.
- How empties return, and the written rule for assigning truck fuel to trays.
What should your first report say?
Four lines: the trays bought this year and their cradle-to-gate emissions, reported in the year of purchase; the per-trip figure with its inputs and the transport rule stated; the waste figure split into recycled, disposed and lost; and the trips per tray your fleet achieved, since that one number moves the rest. Leave out borrowed percentages from other products. For how trays fit into the rest of a bakery’s operation, start from what a commercial bread tray does after the oven.