Hotspot definition consideration as related to estimation of different emission sources (how emissions are estimated vs. cutoff criteria if certain emission sources are included).

The 28th session of the Informal Working Group on Automotive Life Cycle Assessment convened on 8th October 2025 from 12:00 to 15:00 via web. The agenda includes welcome and introduction, adoption of the agenda and last meeting minutes, review of open issues, review of all development of amendment proposal, and discussion of whether to keep the original schedule or extend activities until next GRPE.

“Hotspot” means a process or stage within a defined boundary exhibiting GHG emissions significantly higher than the average. A process or stage shall be included in the calculation if recognized as necessary to satisfy the requirement definition of the cut-off rule in 7.13, even if not considered a hotspot in GHG emissions calculation. Hotspots are defined in the 2017 UNEP report, and hotspot definition may be revised considering updated references.

Hotspot means a life cycle stage whose contribution to an impact category exceeds even distribution across all stages, or all stages collectively contributing more than fifty percent to any impact category. In vehicle LCA guidelines for Global Warming Potential, hotspots refer only to the production phase and are related to parts or components representing minimum twenty percent of Global Warming Potential of the production phase. Level three requires company-specific data for at least one hotspot material or component, with primary data preferred and secondary data traceable and based on field survey data when primary data unavailable.

A-LCA SG2 comments. Results of A-LCA based on this Resolution shall be completely and accurately reported without bias in accordance with paragraph 6 “Reporting” of ISO 14040: 2006. Results, data, methods, assumptions and limitations described in the background report shall be transparent and presented in sufficient detail to allow readers, reviewers, verifiers and the targeted audience to comprehend the determination process and its complexities and trade-offs inherent in the LCA. The background report is the basis for critical review and verification for all levels of the level concept. When results of the A-LCA are available to the public, required information shall be described within the background report and in a summary report, including general information, applicable methodology, vehicle configuration, geographic considerations, results, data sources and weighting factors, and reviewer or verifier signature.

Section 10 establishes that verification shall be conducted to confirm A-LCA results comply with the Resolution while ensuring transparency and consistency. For levels 1, 2, 3 and 4, a critical review shall be conducted according to ISO 14040:2006 paragraph 7 with additional focus on compliance. The verification statement shall be available on published A-LCA study reports. Verification covers methodology applied, input data used, interpretation of results, interpretation of robustness, reporting in background reports, and checking numerical calculation results. For levels 1 and 2, LCA practitioners should decide whether to perform internal or external critical review; for levels 3 and 4, external third-party review is mandatory. For levels 3 and 4, verification shall be conducted at OEM level and shall include definition of the LCA group and choice of representative vehicle. Verification at OEM level shall build on verifications of suppliers’ input data without re-verifying these data. The OEM’s LCA calculation system verification shall include data collection, internal sources, assumptions, calculation processes and tools applied. In case an LCA calculation system is verified and verification remains valid, no reverification is required for subsequent LCA studies based on that verified system. OEMs and suppliers shall make system verification statements available to contracting parties upon request.

Section 7.9 establishes a representative vehicle (RV) methodology for Automotive Life Cycle Assessment. The RV is a benchmark vehicle reflecting typical characteristics of a defined group of vehicles to reduce administrative burden while ensuring comparability. RV selection excludes high-performance, off-road, and special-purpose variants, then selects based on highest technical mass among remaining vehicles within an LCA group defined by vehicle structure family, powertrain type, and production region. Upstream, downstream, and end-of-life emission factors are calculated from the RV and applied to declared vehicles within the same LCA group. Traction batteries and hydrogen storage vessels are calculated separately.

Proposal to establish a new Mutual Resolution concerning Automotive Life Cycle Assessment (A-LCA) to provide an internationally harmonised methodology for determining the carbon footprint of light-duty vehicles across all life cycle stages—material production, parts production and vehicle assembly, use, and end-of-life—considering energy use pathways from production to disposal, with a Level Concept offering four detail levels depending on data availability and study purpose, including definitions, abbreviations, system boundaries, data collection requirements, energy modelling approaches for electricity and fuels, allocation rules, waste treatment and recycling modelling using Circular Footprint Formula or Recycled Content Method, maintenance assessment, and verification procedures. The methodology applies to light-duty vehicles, uses a functional unit of 1 passenger per kilometre over vehicle lifetime, includes service life values from official data by Contracting Parties or peer-reviewed reports, accounts for discrepancy and deterioration factors in use phase calculations, addresses traction battery and fuel cell deterioration, specifies reporting requirements for all life cycle stages including biogenic emissions separately, and requires external third-party verification for Level 3 and Level 4 studies based on GRPE/86/Rev.1 through the Working Party on Pollution and Energy at its 93rd session.

OICA comments on SG4 Use Phase inputs to GRPE/2025/17 concern vehicle service life definitions, discrepancy and deterioration factors for real-world energy consumption, battery state-of-health degradation for off-vehicle charging hybrid electric vehicles, hydrogen and methane leakage quantification, refrigerant emissions from air conditioning systems, and maintenance parts replacement methodologies. OICA advocates for regional flexibility in service life determination, OEM-specific data for discrepancy factors at Level 4, standardized approaches for battery and fuel cell deterioration, and structured hierarchies for assessing maintenance part replacements over vehicle operational lifetime.

Proposal to define service life for each region or country of usage based on average vehicle age at recycling point, establish methodologies for calculating deterioration factors for fuel cell hybrid electric vehicles and off-vehicle charging hybrid electric vehicles, exclude traction battery and fuel cell system replacement by default unless practitioners provide detailed justification grounded in empirical field study data or official manufacturer statements concerning durability and replacement practices, and clarify that for Japan, no statistics on service life in kilometres or years are currently available, requiring use of default regional values or peer-reviewed alternatives where Japanese data cannot be obtained.