Metrics for measuring ESG impacts in sustainability reports

Sustainability reports use different metrics to assess and monitor the environmental, social and governance (ESG) impacts of organizations. The metrics are based on international standards such as the Global Reporting Initiative (GRI), the Sustainability Accounting Standards Board (SASB), the Task Force on Climate-related Financial Disclosures (TCFD) and the Greenhouse Gas (GHG) Protocol for measuring greenhouse gas emissions.

In addition, the European Sustainability Reporting Standards (ESRS), developed under the Corporate Sustainability Reporting Directive (CSRD), provide a regulatory framework for ESG reporting in Europe. The metrics are also aligned with the Sustainable Development Goals (SDGs) of the United Nations, promoting sustainable and responsible business practices.

Below is a list of the main metrics used to measure impacts in the different areas of interest, with the relative units of measurement and benchmarks.

Environmental impacts

Emissions and energy

The GHG Protocol classifies emissions into three scopes, with standardized metrics:

Scope 1 (direct emissions): combustion of fuels in own facilities, measured in tons of CO₂ equivalent (tCO₂e). For refrigerants, the IPCC global warming potential (GWP) is applied, such as 1,530 for R134A2.
Scope 2 (indirect energy emissions): calculated using a location-based (national emission factors) or market-based (supplier-specific energy mix) methodology. In 2025, the Italian factor for electricity is 268 gCO₂e/kWh².
Scope 3 (value chain): includes business travel (tCO₂e/passenger-km) and supplier emissions, aligned with ISO 14064.

ESRS E1 requires disclosure of reduction targets based on the Science Based Targets initiative (SBTi), with trajectories compatible with the Paris Agreement.

Energy consumption: expressed in megawatt-hours (MWh) or joules (J), with a distinction between renewable and non-renewable energy (GRI 302-1, SASB, ESRS E1-5).
Energy efficiency: reduction of energy intensity per unit of production or revenue (kWh/unit produced) (GRI 302-3).

Pollutants

Emissions of air pollutants: measured in tons per year (t/year), including SOx, NOx (GRI 305-7, monitored according to EU Directive 2016/2284 on national limits, European Pollutant Release and Transfer Register – E-PRTR, ESRS E2-2)
Concentration of particulate matter (PM2.5/PM10) at production sites (unit: µg/m³), compared with World Health Organization limits.
Spills and releases of hazardous substances: number of incidents and volume released in liters or cubic meters (L or m3) (GRI 306-3).

Water

Water consumption: expressed in cubic meters (m3) of water withdrawn, used and recycled with disaggregation by source (aqueduct, groundwater, recycling). (GRI 303-3, 303-5, Alliance for Water Stewardship – AWS, ESRS E3-5).
Water intensity in high stress areas (unit: m³/€ of added value), calculated using the Aqueduct Water Risk Atlas.
Water discharge: volume in m3 and concentration of main pollutants such as BOD, COD, total suspended solids (GRI 303-4, European Water Framework Directive).
Percentage of wastewater treated (unit: %), in accordance with GRI 303 Standards.

Waste and materials

Waste production: measured in tons (t), divided into hazardous and non-hazardous (GRI 306-2, Basel Convention, ESRS E5-2).
Recycling and reuse: percentage of recycled or reused waste out of the total produced, with distinction between materials (plastic, metals, paper) (GRI 306-4, Circular Economy Indicators).
Waste intensity per product unit (unit: kg/unit), monitored according to EMAS Criteria.
Use of sustainable materials: percentage of recycled or certified materials in production processes (GRI 301-2, Cradle to Cradle Certification).

Biodiversity

Area of natural habitat impacted: expressed in hectares (ha) of territory affected by company activities according to parameters established by the Taskforce on Nature-related Financial Disclosures (TNFD) which refers to the application of the IBAT (Integrated Biodiversity Assessment Tool) (GRI 304-1, ESRS E4-1).
Environmental offsetting: number and type of environmental restoration projects implemented (GRI 304-3, Convention on Biological Diversity – CBD).
Investments in ecological restoration projects (unit: €/year), aligned with the Global Biodiversity Framework 2022.
Protected species and habitats at risk: number of species and habitats affected by company operations (GRI 304-4, International Union for Conservation of Nature – IUCN Red List).

Social impacts

Employees

Health and safety at work: number of accidents at work, accident frequency and severity rate (GRI 403-9, ISO 45001, ESRS S1-14).
Rate of recordable injuries (unit: cases/200,000 hours worked), aligned with SDG 8.8.
Gender equality and inclusion: percentage of women in leadership positions (GRI 405-1, ESRS S1-16).
Gender pay gap (unit: % compared to male pay), with sector benchmarks from Eurostat.
Training and development: average hours of training per employee, broken down by gender and role (GRI 404-1, ESRS S1-13).

Workers in the value chain

Working conditions and human rights: percentage of suppliers compliant with international labor standards (GRI 414-1, ILO Core Conventions, ESRS S2-3).
Audits on the supply chain: number of ESG audits carried out on suppliers (GRI 308-2, ESRS S2-4).
Percentage of suppliers subject to social audits (unit: %/year), with criteria on child labor and safety (SA8000 Standards).
Days of work lost due to occupational illness (unit: days/year), related to investments in training on PPE.

Consumers and end users

Product safety and quality: number of product recalls for non-compliance (unit: number/year), managed according to EU Directive 2023/988 on producer responsibility (GRI 416-1, ISO 9001, ESRS S3-1).
Investments in sustainable innovation (unit: €/year), linked to the reduction of the environmental footprint of products.
Privacy and data protection: number of data security breaches and privacy complaints (GRI 418-1, GDPR, ESRS S3-2).

Community

Investments in the community: expenditure in euros (unit: €/year), including taxes, donations and welfare programs for social projects and local development initiatives (GRI 413-1, ESRS S4-1).
Involvement of local stakeholders: (unit: number of initiatives/year), with reference to the OECD Due Diligence Guidelines, number of meetings and consultations with local communities (GRI 413-2, ESRS S4-2).

Governance impacts

Corporate culture and conduct

Corporate ethics policies: existence of codes of ethics and training on corporate values (% of employees trained) metric of coverage of codes of ethics (unit: % of employees trained/year), with verification through ISO 37001 (GRI 205-2, ESRS G1-1).
Reports of ethical violations: number of reports and corrective actions taken (GRI 2-26, Whistleblowing Protection Laws).

Supplier relationship management

ESG compliance audit of suppliers: percentage of suppliers monitored and results of assessments (GRI 414-1, ESRS G2-2).
Average days of payment (unit: days), monitored according to EU Directive 2023/123 on commercial delays.
ESG clauses in contracts (unit: % of total), with penalties for non-compliance.

Payment practices

Effective Tax Rate (unit: %), compared with the statutory rate to identify avoidance practices.
Reserves for tax disputes (unit: €), disclosed according to IFRS.

Corruption and lobbying

Number of cases of corruption and fraud: (units: number/year), broken down into cases of active (bribes) and passive (accepting favors), investigations initiated and sanctions applied (GRI 205-3, Transparency International, ESRS G1-2).
Expenditure on lobbying (unit: €/year), with details on the issues promoted (e.g. energy transition) (GRI 415-1, OECD Guidelines, ESRS G1-5, SASB IF-ES-420a-2).
Contributions to political parties (unit: €/year), published in accordance with EU Regulation 2022/2524 on transparency.

Integrating ESG metrics with the Sustainable Development Goals (SDGs) requires the adoption of hybrid indicators such as the SDG Contribution Score, which measures the percentage of revenue aligned with UN goals (unit: % of turnover).