The GHG Protocol classifies Scope 3 emissions into 15 categories. It is not realistic for manufacturers to measure all categories simultaneously, making it essential to set priorities by combining emissions materiality (significance) with measurability. In the manufacturing sector, Category 1 (purchased goods and services) and Category 11 (use of sold products) typically account for the majority of total emissions, though the distribution varies significantly by industry.
Overview of All 15 Scope 3 Categories
The GHG Protocol's Scope 3 is divided into upstream (Categories 1–8) and downstream (Categories 9–15). Upstream categories relate to emissions associated with what the company purchases and uses; downstream categories relate to emissions associated with what the company sells and provides.
Upstream Categories (Cat. 1–8):
- Cat. 1: Purchased goods and services
- Cat. 2: Capital goods
- Cat. 3: Fuel- and energy-related activities not in Scope 1 or 2
- Cat. 4: Upstream transportation and distribution
- Cat. 5: Waste generated in operations
- Cat. 6: Business travel
- Cat. 7: Employee commuting
- Cat. 8: Upstream leased assets
Downstream Categories (Cat. 9–15):
- Cat. 9: Downstream transportation and distribution
- Cat. 10: Processing of sold products
- Cat. 11: Use of sold products
- Cat. 12: End-of-life treatment of sold products
- Cat. 13: Downstream leased assets
- Cat. 14: Franchises
- Cat. 15: Investments
While Cat. 1 and 11 are the two dominant categories for manufacturers, the weight of Cat. 4 (transportation), Cat. 3 (energy-related), and Cat. 12 (end-of-life treatment) also varies by industry.
Material Scope 3 Categories for Manufacturers
Category 1: Purchased Goods and Services
Emissions associated with the production of raw materials, components, and outsourced services. Typically the largest category for manufacturers, accounting for 50–80% of total Scope 3. It can be estimated by multiplying activity data (procurement volumes) by emission factors, though accessing supplier-specific data remains a challenge. Companies that procure large volumes of energy-intensive materials (steel, aluminum, chemicals) will have larger Cat. 1 emissions.
Category 11: Use of Sold Products
For products such as automotive components and electrical equipment that consume electricity or fuel during use, this can be the largest category. For automotive Tier 1 suppliers, Category 11 may drop sharply with electrification (for engine parts) or change in other ways (for components with electricity consumption). This is the category where OEM requests for data are most specific, and companies are increasingly required to certify the emission intensity of their products.
Category 4: Upstream Transportation and Distribution
Emissions from transporting raw materials and components to the factory. For manufacturers with a high global procurement ratio, this can account for 10–20% of Scope 3. The basic calculation is ton-kilometers multiplied by emission factors, requiring data collection from logistics providers. When the proportion of air freight is high, emissions can be disproportionately large. Reduction measures can be designed in conjunction with green logistics initiatives (fuel-efficient trucks, shift to sea freight).
Category 12: End-of-Life Treatment of Sold Products
Emissions from product disposal and recycling. Particularly important for manufacturers handling significant volumes of chemicals, electronics, and packaging materials. Estimating disposal volumes involves calculations using market residual quantities and disposal rates, and accuracy is often low. Reduction targets can be set in conjunction with circular economy initiatives (promoting recycling, extending product life).
Distribution of Key Categories by Industry Sector
The distribution pattern of Scope 3 varies considerably by industry. It is important to select categories appropriate to your company's industry characteristics.
Materials and Chemical Manufacturers
Cat. 1 (raw materials) is the largest. Petroleum, natural gas, and mineral raw material emissions dominate. Cat. 11 (use) varies by product characteristics, but emissions from chemical disposal and degradation (Cat. 12) may also be significant. Cat. 3 (energy-related) is also high.
Automotive Parts Manufacturers (Tier 1 to Tier 2)
Cat. 1 (procurement of steel, aluminum, resin, and other materials) is the largest. Cases are increasing where OEMs request data on the contribution to Cat. 11 (vehicle in-use emissions). Cat. 4 (transportation from global procurement) is also non-negligible.
Electrical and Electronic Equipment Manufacturers
Cat. 11 (electricity consumption during product use) is often the largest. Cat. 1 (electronic components and semiconductors) is also significant. Improving product energy efficiency is the primary reduction lever for Cat. 11, making coordination with product design critical.
Food and Beverage Manufacturers
Cat. 1 (agricultural products, livestock products, packaging materials) is the largest. Converted emissions from agricultural methane (CH4) and nitrous oxide (N2O) are substantial. Cat. 4 (logistics) is also important. Cat. 12 (food waste) is a challenge linked to food loss reduction.
Measurement Difficulty and Priority Matrix
Category prioritization is determined by two axes: the magnitude of emissions and the feasibility of measurement. For categories where emissions are large but data acquisition is extremely difficult, it is practical to defer near-term action; categories with moderate emissions but higher measurability should be addressed first.
Conduct a materiality assessment
Assess the significance of emissions (using industry-specific emission factor databases for estimation) and measurability for all 15 categories, then narrow down to 3–5 categories to address in the near term. Review annually and gradually expand the measurement scope. Initial screening using GHG Protocol screening analysis tools or the ILCD database (Europe) and SuMPO database (Japan) is effective as an entry point.
Start with Category 1 calculations
Procurement data (procurement volumes and amounts) often exists within the company, and a preliminary estimate can be made using emission factor databases (SuMPO environmental labels, ecoinvent, etc.) without requesting data from primary suppliers. Prioritize scope over precision and capture the full volume first. Extracting procurement data from procurement management systems combined with item-level emission factor tables is the most standard calculation method.
Progressively collect primary supplier data
To improve accuracy, begin collecting proprietary emissions data from suppliers representing the top 20% of procurement spend. Using formats from JAMA, JEITA, and similar organizations can reduce collection effort. Actively utilize shared data portals if they exist across multiple business partners. Data requests to suppliers are better received when framed as 'a collaborative effort to jointly understand emissions' rather than 'a demand for improvement.'
Scope 3 Reduction — Linking Target-Setting with Measures
Beyond disclosure, business partners and investors are increasingly requiring the setting of reduction targets and the implementation of measures. Designing these in coordination with SBTi Scope 3 reduction targets (such as a reduction of 40% or more across the entire value chain) leads to high evaluations under international standards.
Reducing Cat. 1 emissions primarily involves "green procurement (switching to low-carbon raw materials)" and "supporting decarbonization among suppliers." Reducing Cat. 11 emissions is linked to "energy-efficient product design," "extending product life," and "solutions for switching in-use electricity to renewables."
The Practical Answer on Disclosure
Aiming for complete disclosure across all 15 categories can require 3–5 years of preparation. The practical approach is a combination of "having measured the significant categories" and "transparently disclosing the scope of measurement and the calculation methodology." Even under ISSB/SSBJ standards, measurement of all categories is not mandatory — rather, focusing on material categories and explaining the calculation methodology are what is required. Encouraging procurement counterparts to move from "Scope 3 not yet addressed" to "key categories measured, calculation methodology clearly stated" is the realistic goal for procurement engagement from 2026 to 2028. Formalizing a schedule for expanding disclosure scope — such as "2026: measure Cat. 1 and 11; 2027: add Cat. 4 and 12; 2028: complete screening of all categories" — and presenting it to investors and business partners functions as effective progress communication.