Plastic:

RMI collaborated with Amcor to pilot plastic product-level greenhouse gas (GHG) data reporting following RMI’s Plastics Extrusion and Molding Greenhouse Gas Emissions Reporting Guidance (hereafter Plastic Conversion PCF Guidance). This guidance covers the conversion process in which plastic resin pellets are formed into the final product shape and its key inputs.

The pilot tested emissions calculations for a plastic container and lid made from polypropylene, comparing across two different plastic sources (virgin plastic and biobased plastic) and two US-based production sites (Syracuse, NY, and Evansville, IN). It helped Amcor gain insights into upstream emissions, deepen supplier relationships, and highlight opportunities for improved data collection, calculation, and climate transparency. It enabled Amcor to explore how product-level emissions data can inform low-carbon procurement and support progress toward its goal of a 32.5% reduction in Scope 3 emissions by 2033 (from a 2022 baseline). Strategically, the pilot strengthened Amcor’s readiness for emerging policy and market demands, such as product carbon footprint (PCF) disclosure and growing customer interest in low-carbon plastics.

Plastics production currently accounts for over 4% of GHG emissions, a share that continues to rise faster than other oil and gas products due to increasing demand in major end-use sectors such as packaging, textiles, and construction materials. The embodied emissions of an otherwise identical plastic product can vary significantly depending on the fossil feedstock type, extraction practices, monomer plant operations, methane management performance, and the electricity sources in downstream processes like molding and extrusion. Reducing climate risk requires both cutting unnecessary plastic use and lowering emissions from essential products. Yet climate pollution from production remains underrecognized in plastics, often overshadowed by concerns around waste and recycling. Despite existing emissions accounting standards and guidance, companies often lack the tools to assess plastic products' climate impact. Gaps remain particularly in the conversion step, which accounts for up to 38% of a plastic product’s embodied emissions. This is especially true when it comes to capturing methane intensity and evaluating recycling methods that align with the sector’s decarbonization pathways. These gaps hinder informed, low-emissions purchasing and design decisions. To address these challenges, RMI and Amcor pilot-tested RMI’s Plastic Conversion PCF Guidance with emissions collected from suppliers to explore practical emissions reporting and how it can drive industry decarbonization.

• RMI’s Plastic Conversion Guidance focuses on the product conversion stage and required Amcor to collect upstream data (e.g., steam cracking, polymerization) to complete product-level emissions calculations. While Amcor requests PCF data (tCO₂e/ton resin) from all suppliers and provides guidance (e.g., recommending the TfS, ISO standard) to meet growing downstream demand, data availability, quality, and consistency still vary. This pilot required reporting of upstream data against the Together for Sustainability’s PCF guidance. It enabled deeper engagement with upstream suppliers, improved understanding of their PCF capabilities, and helped streamline internal coordination within Amcor. By encouraging suppliers to engage more deeply on emissions data, the pilot helped drive improvements of upstream emission transparency and align with reporting standards.

• Verifying the accuracy of collected upstream data remains a key challenge. To strengthen confidence in upstream data where third-party verification is lacking, RMI’s guide for assessing oil and gas input variability and updated tool can be used to help resin converters understand emissions differences and ranges in key feedstocks.

• The Excel-based calculation tool provided by RMI enabled Amcor to calculate key metrics aligned with the Plastic Conversion PCF Guidance. In support of RMI’s reporting guidance, the calculation tool generated key outputs, including emissions intensity from raw material extraction through conversion, methane leak intensity, and primary data share, aligning emissions tracking to support decarbonization targets. By shifting from regional averages and proprietary tools to supplier-specific data and RMI’s open-source approach, Amcor enhanced the consistency and credibility of its product carbon footprints and improved Amcor’s ability to identify emissions drivers. Amcor regularly used site locations to apply location-specific power grid emissions factors to calculate their conversion site Scope 2 emissions prior to this pilot. This new tool aligned with the Plastic Conversion PCF Guidance builds upon this capability, adding path-specific yet comparable variations in upstream methane, base resin, and additive emissions inputs.

• Like-for-like comparability is key for benchmarking PCFs, achieving targets, and making credible procurement decisions. A major challenge is that suppliers often report average PCFs that don’t reflect specific production paths for resin grades, despite wide variation of emissions within the same polymer type due to factors like calculation methodology, energy attributes, and primary feedstock characteristics. This underscores the need to specify accounting methods, chain-of-custody models, and disaggregated key variable inputs in emissions reporting.

• The pilot also identified notable discrepancies between data sources of differing quality for the same plastic type. Primary data from facility measurements and supplier PCFs offered detailed, process-specific insights, while secondary data from LCA modeling tools and reported literature was more generic and averaged. ^{RMI’s OCI+ tool provided regional emissions estimates based on the O&G source location. Additionally, where refining and petrochemical processing data is lacking, DOE’s GREET model and University of Calgary’s refinery model were used to determine feedstock conversion factors. 1} Secondary data quality varied widely in geographic granularity and independent validations. Exhibit 2 below highlights emissions differences for the cradle-to-gate carbon intensity of a virgin polypropylene container. Using primary data resulted in lower emissions intensity of the fossil virgin product than when secondary data was used. Additionally, the use of primary data resulted in an embodied methane value three orders of magnitude larger than when solely secondary data was used. This suggests that primary data has the potential to help some suppliers more accurately reflect their performance. Where feasible, the use of primary data should be encouraged.

• At a time when PCF data is still difficult to access and standardize, collecting additional metrics, such as energy and feedstock inputs, recycling methods, and methane intensity, can be challenging, but highly valuable. These metrics offer deeper insights into key emissions hotspots, material choices, and overlooked sources like methane, supporting more informed and lower-carbon procurement decisions. Since most downstream customers still request only a single PCF number, building the case for these additional metrics is essential to accelerate adoption and drive market transformation.

• For example, methane intensity is a powerful yet often underreported metric that is essential to reflecting the full climate impact of fossil fuel extraction and processing. During this pilot, primary data for these metrics could not be collected due to limited visibility into supplier data far upstream. Based on RMI’s recommendation, the pilot used RMI’s OCI+ tool to determine basin-specific and refining methane emissions and RMI’s ClimateWorks chemical model based on GREET for steam cracking methane emissions. Additionally, Scope 2 methane emissions were determined using region-specific residual grid factors. Amcor required support from RMI to effectively use OCI+ and GREET, demonstrating the need for training and capacity building in the use of these (and similar tools). RMI addressed this need by creating a methane intensity guide within the Excel tool instructions.

• The calculation results show that methane emissions made up less than 5% of total CO₂-equivalent emissions using a 100-year global warming potential (GWP) but rose to 8% when assessed using a 20-year GWP basis. Considering most accounting standards use a 5% cutoff, this suggests existing reporting and decision-making based only on 100-year GWP CO₂ equivalency is not sufficient to manage current methane pollution effects for the fastest-growing oil demand driver. Additionally, though including upstream methane leaks in PCF calculations is required under TfS, it is optional for PACT methodology, creating an opportunity for underreported emissions intensities. This further highlights the need for consistent and thorough methane reporting across methodologies.

The pilot revealed two key challenges that need to be addressed to scale impact.

• Because data related to optional guidance metrics (e.g., renewable energy share, use intensity, end-of-life) and methane intensity are rarely requested, much of the requested supplier emissions were not readily available. Without clear demand/economic signals, it’s difficult to create consistent market pressure on high-carbon suppliers. Companies acting alone lack the volume or influence to shift supply chains, but collectively, buyers can send stronger signals and prioritize low-emission suppliers, as shown by incentives like the U.S. Plastic PACT.

• There were several observed gaps in product-level reporting, where key data points across the supply chain weren’t captured. While current regulatory efforts are limited on emission transparency policies, policy momentum is building, evidenced by the advancing of the EU’s CBAM (which may expand to the organic chemical sector), Oregon’s Packaging LCA regulations, and the U.S. Plastics PACT. Most companies are not yet prepared for the data, transparency, and emissions performance expectations that are likely coming. Bridging this awareness gap, and helping companies prepare for regulatory and buyer scrutiny, will be critical for accelerating adoption of product-level emissions metrics and advancing decarbonization across the value chain.

• Encourage PCF methodology standardization through commercial and industry collaboration: Amcor will encourage suppliers to adopt standard industry practices, such as the TfS guidance, for upstream data collection to improve consistency and comparability. Further, for the conversion step, Amcor may work to apply the pilot reporting practices, with a focus on scalability both within the organization and across broader industry efforts. Amcor intends to also expand supplier engagement, procurement contracts, and events to promote alignment on PCF methods.

• Promote standardized PCF data sharing: The company should explore automation, interoperable data formats, and digital product passports that include PCF information at the point of purchase. It can also consider blockchain or other digital tools to enhance transparency, reduce administrative burden, and accelerate market adoption. A PACT-aligned digital format is available for the Plastic PCF Conversion Guidance to facilitate automated data transfer between companies and was not tested for this pilot but can be considered in future tests.

• Collaborate with downstream buyers to send demand signals for low-carbon resin options: Work with downstream buyers to align on data needs, climate claims, and shared expectations for low-carbon materials, strengthening demand signals across the value chain.

• Promote standardization of PCF methodology for plastic conversion and transparency in climate-related metrics: RMI would like to demonstrate the broader applicability of PCF guidance across all plastic types, not just polypropylene and packaging. Further, RMI will advocate for more granular, harmonized PCF reporting practices to enable fair comparisons among suppliers and support data-driven procurement decisions.

• Strengthen demand signals through aggregation efforts: RMI will collaborate with downstream buyers and industry coalitions to aggregate demand for low-carbon and recycled-content plastics following examples of other sectors (e.g., steel, sustainable aviation fuel). RMI will also help buyers align key product performance expectations to show a unified market signal to suppliers, incentivizing the production of lower-carbon materials.

• Advance the market for low-methane-leakage gas: RMI will use insights from the case studies to continue demonstrating the value of methane emissions transparency as a critical lever for emissions reduction. This work will help create an enabling environment for methane mitigation by supporting standardized reporting practices and informing future policy and procurement decisions.