Scope 1, 2 and 3 emissions are a corporate accounting framework, not a process engineering one. That mismatch is why process teams asked to contribute to a disclosure often struggle: the categories do not line up with how a bioprocess is designed or operated.
This article maps a bioprocess onto the three scopes input by input, and shows how a process life cycle assessment converts into a scope inventory without recollecting the data.
What the three scopes actually mean
The GHG Protocol Corporate Standard divides emissions by who controls them, not by where they physically occur.
- Scope 1 — direct emissions from sources you own or control. Gas burned in your own boiler, your own vehicle fleet, refrigerant leakage from your own chillers.
- Scope 2 — indirect emissions from energy you purchase. Electricity, purchased steam, purchased heating and cooling. The emission physically happens at a power station, but it is yours because you bought the energy.
- Scope 3 — every other indirect emission in your value chain, split into 15 categories covering purchased goods and services, capital goods, fuel and energy activities, transport, waste, business travel, commuting, use of sold products and end of life.
The boundary that matters is operational control. If you own the incinerator that burns your single-use plastics, that combustion is Scope 1. If a contractor burns them, it is Scope 3. The molecules are identical; the accounting is not.
Mapping a bioprocess onto the scopes
Here is where each input from a typical single-use biomanufacturing process actually lands.
| Process input | Scope | Category / note |
|---|---|---|
| Agitation and aeration electricity | 2 | Purchased electricity |
| Cooling and chillers | 2 | Purchased electricity |
| Cleanroom HVAC | 2 | Purchased electricity. Usually the largest single line. |
| WFI / purified water generation | 2 | Purchased electricity, if electrically driven |
| Natural gas for SIP steam | 1 | On-site combustion |
| Purchased steam | 2 | Not Scope 1, because you did not burn it |
| Refrigerant top-up | 1 | Fugitive emissions, high GWP, easily forgotten |
| Media, buffers, process chemicals | 3 | Cat. 1, purchased goods and services |
| Single-use assemblies (resin production) | 3 | Cat. 1, purchased goods and services |
| Chromatography resin | 3 | Cat. 1 |
| Municipal water supply | 3 | Cat. 1 |
| Wastewater treatment (third party) | 3 | Cat. 5, waste generated in operations |
| Single-use waste incineration (contracted) | 3 | Cat. 5 |
| Single-use waste incineration (own site) | 1 | Becomes direct combustion |
| Bioreactors, skids, facility build | 3 | Cat. 2, capital goods |
| Upstream fuel extraction for your gas | 3 | Cat. 3, not covered by the Scope 1 combustion factor |
| Cold chain distribution | 3 | Cat. 9, downstream transport |
Scope 1 covers boiler gas, refrigerant leakage and own-site incineration and is small for a single-use facility. Scope 2 covers cleanroom HVAC, agitation, aeration, cooling and WFI generation and is the site's biggest lever. Scope 3 covers media, buffers, resin, single-use assemblies and waste treatment and is over 90% at company level.
Why the value chain dominates in pharma
At company level, Scope 3 is over 90% of reported emissions for a typical pharmaceutical company, and roughly 71% of biotech and pharma sector emissions arise in the supply chain. Within it, purchased goods and services is normally the largest single category.
This creates a genuine tension with what a process LCA tells you. Our worked example for a single 2000 L batch found electricity at 95.6% of the cradle-to-gate footprint. At corporate level the picture inverts, and purchased goods dominate. Both are true, and the reason is boundary rather than disagreement.
A process LCA of your own manufacturing step counts the energy you use to run it. A corporate value-chain inventory counts everything embodied in what you buy, including the manufacturing energy of every supplier, the API you in-license, contract manufacturing, packaging, and distribution. The further out the boundary goes, the more of the total sits with someone else.
Get the process-level numbers first
The Bioprocess LCA Calculator gives you the energy, water, materials and waste inventory for a batch. Those are the same figures a Scope 1 and 2 inventory needs, and the starting point for the Scope 3 categories you control.
Four things teams miscount
- Putting purchased steam in Scope 1. If you did not burn the fuel, it is Scope 2. Only combustion in equipment you operate is Scope 1.
- Forgetting refrigerants. Fugitive losses from chillers and cold storage are Scope 1 and carry enormous global warming potentials. Some HFCs exceed 1,000 kg CO2e per kg. A few kilograms of top-up can outweigh a month of gas.
- Counting single-use plastics once. Resin production is category 1 and incineration is category 5. They are separate entries, and omitting the second understates a single-use process substantially.
- Ignoring category 3. The extraction, refining and transport of the gas you burn is not covered by the combustion factor you applied in Scope 1. It is a separate upstream category, typically adding 15 to 20% on top of the combustion figure.
How this relates to a process LCA
A process LCA and a scope inventory are the same underlying data sorted two different ways.
| Process LCA | Scope 1/2/3 inventory | |
|---|---|---|
| Sorted by | Life cycle stage | Who controls the emission |
| Denominator | Per kg of product | Per organisation per year |
| Boundary | Cradle-to-gate for one process | Whole company, all activities |
| Used for | Process decisions, comparisons | Disclosure, targets, CDP and CSRD |
| Dominant term | Electricity, for a bioprocess | Purchased goods, at company level |
Converting one batch into scope lines
Taking the 2000 L single-use batch from our worked LCA, on a 400 g CO2e/kWh grid:
Scope 2 28,759 kWh × 400 g/kWh = 11,504 kg CO₂e
Scope 3 media + resin (cat. 1) = 238 kg CO₂e
Scope 3 water supply + treatment (cat. 1 / 5) = 51 kg CO₂e
Scope 3 single-use incineration (cat. 5) = 243 kg CO₂e
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Batch total = 12,036 kg CO₂e
For this fully single-use process, Scope 1 is zero because nothing is burned on site. That is a real and slightly uncomfortable result: switching from stainless to single-use moves emissions out of Scopes 1 and 2 and into the value chain, which can improve the numbers a company reports most prominently without reducing total emissions at all.
Where to act first
For a manufacturing site, Scope 2 electricity is almost always the largest line you control directly, and it responds to two levers immediately: siting and procurement. Moving the same process between grids changes its footprint several-fold, and a renewable power purchase agreement changes it without touching the process at all.
The value chain matters enormously for disclosure and for science-based targets, but it depends on supplier data most organisations do not yet hold. The practical sequence is: get Scope 2 right and act on it, build Scope 1 from meter and refrigerant records, then work outwards from your largest spend categories.
See the full worked assessment
Our life cycle assessment example runs this same batch through all four ISO 14040 phases, showing where each of these numbers comes from.
Frequently asked questions
What are Scope 1, 2 and 3 emissions?
Scope 1 is direct emissions from sources you own or control. Scope 2 is indirect emissions from purchased energy. Scope 3 is everything else in the value chain across 15 categories. The framework comes from the GHG Protocol Corporate Standard and divides by control, not geography.
Which scope does electricity for a bioreactor fall into?
Scope 2, always, for purchased electricity, whatever it powers. Agitation, aeration, cooling, HVAC and water generation all sit there. Generate electricity on site by burning gas and the combustion becomes Scope 1 instead.
Why is Scope 3 so large for pharmaceutical companies?
Pharmaceutical manufacturing buys far more than it burns. It is over 90% of a typical pharmaceutical company's reported emissions, with roughly 71% of sector emissions arising in the supply chain, and purchased goods and services is normally the largest category within it.
Are single-use plastics Scope 1 or Scope 3?
Both, at different points. Resin and assembly production is category 1. Incineration is category 5 if contracted out, or Scope 1 if you operate the incinerator. Counting only one of the two is a common error.
How does a process LCA relate to Scope 1, 2 and 3?
Same data, different sort. A process LCA groups by life cycle stage per kg of product; a scope inventory groups by control boundary per organisation per year. Building one gives you most of the other.
Do I need Scope 3 data to reduce my footprint?
Not to start. Scope 2 electricity is the largest line a site controls directly and responds immediately to siting and procurement. Value-chain data is essential for disclosure and targets but depends on suppliers you may not have engaged yet.
References
- Greenhouse Gas Protocol. Corporate Accounting and Reporting Standard, and Corporate Value Chain (Scope 3) Standard. ghgprotocol.org
- Pharmaceutical Supply Chain Initiative. Scope 3 greenhouse gas emissions calculation: guidance for the pharmaceutical sector. pscinitiative.org
- Booth, A. et al. (2023). Pharmaceutical Company Targets and Strategies to Address Climate Change. PMC9967855