Calculation Methodology

All fuel factors use ADEME Base Carbone V23.6 (2025) full lifecycle methodology, which includes combustion CO₂, CH₄, N₂O (IPCC AR5 GWP100) plus upstream extraction and transport emissions. This is more conservative than DEFRA combustion-only Scope 1 factors and is the standard approach in French/EU GHG accounting.

Covers fuel used in vehicles owned or leased by the company (fleet vehicles). Employee personal vehicles reimbursed per km are reported in Scope 3.

Refrigerant leaks are high-impact Scope 1 emissions due to the very high Global Warming Potential (GWP) of hydrofluorocarbons. Factors are GWP100 values from IPCC Fifth Assessment Report (AR5, 2013), which is the current standard required by UNFCCC and GHG Protocol.

Uses the average emission factor for the national or regional electricity grid in the country where the energy was consumed. See Section 2 for the full country-specific factor table. This is the default method and the one most commonly required by buyers for Scope 3 Category 3 reporting.

The market-based method uses the emission factor attached to the specific energy contract: near zero for electricity covered by a Guarantee of Origin, a REC or a PPA, and the country's published residual mix factor for everything not covered by one.

VSME OS does not currently report a market-based figure. The residual mix is the reason it cannot simply be added: once every certificate in a country has been stripped out of the pool, what is left is dirtier than the grid average — so the market-based figure is frequently higher than the location-based one, dramatically so in countries that export most of their guarantees of origin. A market-based figure built by zero-rating contracted electricity and leaving the rest at the grid average would flatter every supplier who has a contract and understate every supplier who does not. Adding it properly means adding the published residual mix data, and that is planned work.

Until then, every Scope 2 figure this product produces is location-based, is labelled as such, and applies the country grid average to all electricity — including electricity bought under a renewable contract. That is the figure the EU VSME standard asks for at §33(b), and the one a buyer needs for their own Scope 3 Category 3 calculation. A supplier's renewable contract is still disclosed: it appears as the renewable share of energy consumption in the §32 energy table.

VSME OS splits flights into short-haul (under 3,700 km) and long-haul (3,700 km and above). This split matters because:

• Short-haul flights are less fuel-efficient per km (more fuel consumed during takeoff and landing relative to total flight distance)
• Long-haul flights spend more time at cruising altitude where Radiative Forcing is most significant
• DEFRA/DESNZ 2026 publishes separate factors for each category, and using a blended average misstates emissions for travellers weighted to one haul type

pkm = passenger-kilometre. To calculate: number of return trips × route distance × 2 (for return). Route distances can be found using flight distance calculators or IATA published city-pair distances.

Category 7 is the GHG Protocol's category for emissions from employees travelling between their home and their regular workplace. VSME OS covers two sub-categories:

VSME OS uses the operational control approach(GHG Protocol, Chapter 3). This means the reporting boundary includes all facilities and vehicles over which the company has operational control — typically the company's own offices, production sites, and owned/leased fleet vehicles. It excludes joint ventures and franchise operations unless specified.

These categories are planned for future phases of the VSME OS roadmap. All currently excluded categories are explicitly listed as boundary exclusions in every generated PDF report (Page 4, Section 5).

Collecting a disclosure is not the same as a given supplier having answered it. Each generated report therefore carries a Scope of this Report section listing every one of the eleven disclosures and whether it was reported, reported in part, declared not applicable, or not reported at all.

A report that does not cover the full Basic Module says so in those words. We would rather a buyer see the gap than assume there is none.

Several disclosures are conditional. B4 applies only where the undertaking already reports pollutants to an authority or under an environmental management system; B5 only where it has sites in or near a biodiversity-sensitive area. Where a supplier positively declares that a disclosure does not apply to them, the report records that declaration rather than leaving the section blank.

The same is true of a conditional sub-point. B10 §42(b) asks for the gender pay gap only where the undertaking is already required to report it by EU law (Directive (EU) 2023/970) or national regulation. A supplier under no such obligation declares that, and the report prints the declaration — it does not print a blank where a percentage would be, and we do not ask them for payroll figures they owe nobody.

Annex I marks B3 (energy and emissions), B6 (water) and B7 (resource use and waste) as voluntary for undertakings with ten employees or fewer, and Annex II places them outside the value chain cap at that size. For such an undertaking these disclosures are reported as not applicable, and a buyer may not require them.

Annex II lists, datapoint by datapoint, what a large undertaking may require from a supplier under the value chain cap. Three things VSME OS collects are not on that list: the employee breakdown by country (§40(c)), fatalities (§41(b)), and the gender pay gap (§42(b)).

We collect them anyway, because a supplier who gives them has a stronger declaration. But the product tells the supplier which of their answers a buyer can actually insist on — the cap is only a protection if you know where it sits.

The Comprehensive Module (C1 to C9) is not currently covered. Scope 3 categories beyond business travel and employee commuting — purchased goods and services, upstream transport, use of sold products — are not quantified. Scope 2 is reported on the location-based method only; market-based dual reporting is planned.