Carbon
math.
If you are assessing us as a supplier and need this in a document, ask — we will send the workbook.
New 275 gallon tote: ≈164 lb CO₂e cradle-to-gate. Reconditioned: ≈93 lb. Rebottled: ≈110 lb. Recycled and remoulded: ≈141 lb. So reconditioning avoids ≈71 lb against new, rebottling ≈54 lb, and recycling ≈23 lb. Every input, factor and assumption is below, including the one that most affects the answer.
Step 1 — the footprint of a new unit
| Component | CO₂e |
|---|---|
| HDPE bottle: 38 lb × 1.8 kg/kg | ≈68 lb |
| Blow-moulding process energy | ≈9 lb |
| Galvanised cage: 48 lb × 2.1 kg/kg | ≈100 lb |
| Cage forming, welding, galvanising energy | ≈14 lb |
| Steel pallet: 32 lb (recycled-content steel) | ≈38 lb |
| Assembly, test, packaging | ≈5 lb |
| Credit: end-of-life steel recovery | −54 lb |
| Credit: end-of-life HDPE recovery | −16 lb |
| Net new-unit footprint | ≈164 lb CO₂e |
End-of-life credits applied using the avoided-burden approach, which is the convention that favours the new unit — we have deliberately not chosen the method that flatters us.
Step 2 — the footprint of reconditioning
| Activity | CO₂e |
|---|---|
| Wash: heating 9 gal make-up water + caustic recirculation | ≈11 lb |
| Caustic chemical production, amortised per unit | ≈4 lb |
| Yard handling: forklift diesel, amortised | ≈3 lb |
| Replacement gasket, valve, cap | ≈7 lb |
| Facility energy, amortised per unit | ≈5 lb |
| Pro-rata share of new-unit footprint over 8 lives | ≈63 lb |
| Reconditioned unit footprint | ≈93 lb CO₂e |
| Avoided vs. new | ≈71 lb |
Step 3 — rebottling and recycling, for comparison
Rebottling adds a new bottle (68 + 9 = 77 lb) and the blast-and- recoat process (≈9 lb) to the reconditioning overheads, while still amortising only the cage and pallet across their remaining lives. Net ≈110 lb, so ≈54 lb avoided against new.
Recycling and remoulding recovers the resin but spends granulation, flake washing, drying, pelletising and re-moulding energy (≈31 lb combined), and regrind displaces virgin resin at roughly 0.9 to 1 on a mass basis with a quality downgrade. Net ≈141 lb, so ≈23 lb avoided against new. That three-to-one ratio against reconditioning is the whole reason this company is organised the way it is.
Step 4 — scaling to the cumulative figure
Cumulative avoided emissions are the sum, over every unit we have processed, of the avoidance appropriate to that unit's actual disposition — reconditioned, rebottled, fabricated or recycled — taken from the routing log rather than assumed. At 418,000 units with our historical disposition mix that gives approximately 29,600 tons CO₂e, with a range of 24,100 to 35,000 tons.
Assumptions, stated plainly
- Substitution rate of 1.0. One reconditioned unit displaces one new unit. Standard convention, and optimistic. At 0.85 the per-unit figure falls to ≈60 lb. This is the single biggest lever on the answer.
- Eight service lives per cage. Consistent with our own records. Fewer lives raise the pro-rata share and reduce the saving.
- Industry-average emission factors. Not supplier-specific. Real factors vary with grid mix and process efficiency.
- Freight excluded, inbound and outbound, on both sides of the comparison. Including it would roughly cancel between scenarios but add noise.
- Use-phase excluded. Identical between a new and a reconditioned unit.
- Our building, forklifts and boiler are counted as a cost, not netted off as a credit.
What would make this better
Third-party assurance to ISO 14064 and supplier-specific resin and steel factors. We have neither, and we would rather say so than imply otherwise. If you need assured figures for a regulated disclosure, use our unit counts and tonnages — which are scale tickets and therefore solid — and treat the CO₂e as indicative with its range.
Headline comparison
| Route | CO₂e / unit |
|---|---|
| New manufacture | ≈164 lb |
| Recycled & remoulded | ≈141 lb |
| Rebottled | ≈110 lb |
| Reconditioned | ≈93 lb |
Lower is better. The gap between the bottom two rows and the top one is this company's entire reason for existing.
Factors used
- Virgin HDPE
- ≈1.8 kg CO₂e / kg
- Galvanised steel tube
- ≈2.1 kg CO₂e / kg
- Recycled-content steel
- ≈1.2 kg CO₂e / kg
- HDPE regrind
- ≈0.55 kg CO₂e / kg
- Natural gas, boiler
- 53.1 kg CO₂e / MMBtu
- Grid electricity, MISO
- ≈0.38 kg CO₂e / kWh
Disagree with us
If you think an assumption is wrong, say which one and why. We have changed this workbook twice on customer challenges — once on the substitution rate and once on the end-of-life credit method — and both times the number went down.
Method questions
Why publish the method instead of just the number?
Because a number without a method is a claim, and claims in this area are routinely inflated by a factor of two or three. Publishing the arithmetic means you can argue with a specific assumption rather than with our marketing. It also means we cannot quietly change it.
Where is the weakest assumption?
Substitution. We assume one reconditioned tote displaces one new tote, which is the standard convention and is also optimistic — in reality some buyers would have bought nothing, or bought drums, or bought a cheaper reconditioned unit elsewhere. A more conservative substitution rate of 0.85 would take the per-unit figure from 71 lb to about 60 lb. That is why we publish a range of 58 to 84 and quote the midpoint.
Do you include freight?
No, and that is deliberate. Freight emissions depend entirely on where the customer is, and a tote shipped 1,800 miles has a very different footprint from one collected at the yard. Including a national average would make the figure less useful rather than more. The avoided-manufacturing figure is clean and comparable; the freight is yours to add.
What emission factors do you use?
Published cradle-to-gate factors: approximately 1.8 kg CO₂e per kg for virgin HDPE resin including polymerisation, 2.1 kg CO₂e per kg for hot-dip galvanised steel tube, plus process energy for blow-moulding, welding and assembly at regional grid intensity. The factors are industry-average rather than supplier-specific, which is a limitation we state rather than hide.
The footprint of a new unit, line by line
| Line | Basis | CO₂e |
|---|---|---|
| HDPE bottle | 38 lb × 1.8 kg CO₂e/kg | ≈68 lb |
| Blow-moulding process energy | Regional grid intensity | ≈9 lb |
| Galvanised cage | 48 lb × 2.1 kg CO₂e/kg | ≈100 lb |
| Cage forming, welding, galvanising | Process energy | ≈14 lb |
| Steel pallet base | 32 lb, recycled-content steel at 1.2 kg/kg | ≈38 lb |
| Assembly, test, packaging | Allocated | ≈5 lb |
| Credit: end-of-life steel recovery | Avoided-burden method | −54 lb |
| Credit: end-of-life HDPE recovery | Avoided-burden method | −16 lb |
| Net new-unit footprint | ≈164 lb |
The footprint of reconditioning
| Line | Basis | CO₂e |
|---|---|---|
| Wash: heating ≈9 gal make-up water plus caustic recirculation | Metered, natural gas at 53.1 kg/MMBtu | ≈11 lb |
| Caustic chemical production, amortised per unit | Charge life across dozens of units | ≈4 lb |
| Yard handling, forklift diesel, amortised | Fuel log ÷ units | ≈3 lb |
| Replacement gasket, valve, cap | Component mass × factor | ≈7 lb |
| Facility energy, amortised per unit | Metered ÷ units | ≈5 lb |
| Pro-rata share of original manufacture over 8 service lives | 234 lb gross ÷ 8, adjusted | ≈63 lb |
| Reconditioned unit footprint | ≈93 lb | |
| Avoided against new | 164 − 93 | ≈71 lb |
Rebottling and recycling, for comparison
Rebottling adds a new bottle (68 + 9 = 77 lb) and the blast-and-recoat process (≈9 lb) to the reconditioning overheads, while amortising only the cage and pallet across their remaining lives. Net ≈110 lb, so ≈54 lb avoided.
Recycling and remoulding recovers the resin but spends granulation, flake washing, drying, pelletising and re-moulding energy — ≈31 lb combined — and regrind displaces virgin resin at roughly 0.9 to 1 with a quality downgrade. Net ≈141 lb, so ≈23 lb avoided.
Sensitivity — the assumption that actually drives the answer
Substitution rate: how many new units one reused unit prevents. We quote at 1.0, the standard convention, which is also optimistic — some buyers would have bought nothing, or drums, or a cheaper reconditioned unit elsewhere.
| Substitution rate | Reconditioned | Rebottled | Recycled |
|---|---|---|---|
| 1.00 — every sale displaces a new unit | 71 lb | 54 lb | 23 lb |
| 0.95 | 66 lb | 50 lb | 21 lb |
| 0.90 | 63 lb | 47 lb | 20 lb |
| 0.85 | 60 lb | 44 lb | 19 lb |
| 0.80 | 56 lb | 42 lb | 18 lb |
| 0.70 | 49 lb | 37 lb | 16 lb |
Note that the three-to-one ratio between reconditioning and recycling holds at every rate. The absolute figure is sensitive; the conclusion is not. That is why we are comfortable building a business on the conclusion while publishing a range on the figure.
| Assumption | Base | If it were worse | Effect on the 71 lb figure |
|---|---|---|---|
| Service lives per cage | 8 | 5 | 71 → 58 lb |
| Service lives per cage | 8 | 12 | 71 → 79 lb |
| Make-up water per tote | 9 gal | 23 gal (our 2025 degradation) | 71 → 66 lb |
| Grid intensity, MISO | 0.38 kg/kWh | 0.50 kg/kWh | 71 → 68 lb |
| HDPE factor | 1.8 kg/kg | 1.6 kg/kg | 71 → 65 lb |
| Steel factor | 2.1 kg/kg | 1.8 kg/kg | 71 → 62 lb |
Scaling to the cumulative figure, and every emission factor used
Cumulative avoided emissions are the sum, over every unit we have processed, of the avoidance appropriate to that unit's actual disposition — taken from the routing log rather than assumed. At 418,000 units with our historical disposition mix that gives approximately 29,600 tons CO₂e, with a range of 24,100 to 35,000.
| Input | Factor | Source type |
|---|---|---|
| Virgin HDPE resin | ≈1.8 kg CO₂e / kg | Industry-average cradle-to-gate, incl. polymerisation |
| Hot-dip galvanised steel tube | ≈2.1 kg CO₂e / kg | Industry average |
| Recycled-content steel | ≈1.2 kg CO₂e / kg | Industry average |
| HDPE regrind | ≈0.55 kg CO₂e / kg | Industry average |
| Natural gas, boiler | 53.1 kg CO₂e / MMBtu | Standard combustion factor |
| Grid electricity, MISO region | ≈0.38 kg CO₂e / kWh | Regional average |
| Diesel, forklift and yard | 10.2 kg CO₂e / US gal | Standard combustion factor |
| Sodium hydroxide production | ≈1.1 kg CO₂e / kg | Industry average |
Assumptions, stated plainly
- Substitution rate 1.0. Standard convention and optimistic. The single biggest lever — see the table above.
- Eight service lives per cage. Consistent with our own routing records. Fewer lives raise the pro-rata share and reduce the saving.
- Industry-average emission factors, not supplier-specific. Real factors vary with grid mix and process efficiency.
- Freight excluded, inbound and outbound, on both sides. It depends entirely on where the customer is and including a national average would make the figure less comparable rather than more.
- Use-phase excluded. Identical between a new and a reconditioned unit.
- Our building, forklifts and boiler are counted as a cost, not netted off as a credit.
- No offsets. None purchased, none counted.
Detailed questions
Why publish the method rather than just the number?
Because a number without a method is a claim, and claims in this area are routinely inflated by a factor of two or three. With the arithmetic on the page you can argue with a specific line rather than with our marketing — and we cannot quietly change it.
Where is the weakest assumption?
Substitution. We assume one reconditioned tote displaces one new tote, which is the standard convention and optimistic. A more conservative 0.85 takes the per-unit figure from 71 lb to about 60. That is why we publish a range of 58 to 84 and quote the midpoint.
Why exclude freight?
Because it depends entirely on where the customer is, and a tote shipped 1,800 miles has a very different footprint from one collected at the yard. Including a national average would make the figure less useful. The avoided-manufacturing figure is clean and comparable; the freight is yours to add.
Have the figures ever been challenged successfully?
Twice. A procurement analyst challenged the substitution rate in 2023 and a customer challenged the end-of-life credit method later the same year. Both were right, both times the number went down, and both revisions are in the current workbook.
Can I have the spreadsheet?
Yes. If you are assessing us as a supplier, ask and we will send the workbook rather than a brochure. It is the same document we work from and it includes the sensitivity tables above.
Why use avoided-burden for end-of-life credits?
Because it is the convention that favours the new unit rather than ours, and we would rather our figure survive the unfavourable method than depend on the favourable one. Cut-off or recycled-content methods would both produce a larger apparent saving for us.
Does the eight-lives assumption hold up?
In our routing records, yes — a galvanised cage kept off wet ground routinely outlasts three or four bottles, and bottles get two to three service lives each. We have published a traced history of one cage through six lives over nine years. Five lives instead of eight would take the per-unit figure from 71 to 58 lb.
What about the carbon of your own operation?
Counted as a cost, not netted off as a credit: facility energy, forklift diesel and boiler gas are inside the 93 lb reconditioned figure. What we do not do is subtract our gross emissions from the avoided total and call the result neutrality. We avoid considerably more than we emit, which is a different and more honest sentence.
Assessing us as a supplier?
Ask for the workbook. We will send the spreadsheet, not a brochure.