Although performing validation of an analytical method is a widely accepted standard, assessing and comparing the overall analytical potential covering all validation criteria is not straightforward.

Carbon Footprint Reduction Index (CaFRI) has been presented as a newly developed web tool designed to assess and enhance the sustainability of analytical methods, with a focus on estimating greenhouse gas emissions (available at bit.ly/CaFRI). While many tools exist for evaluating greenness, none specifically address the carbon footprint of laboratory procedures. CaFRI fills this gap by providing a standardized approach that predicts the effectiveness of carbon footprint reduction strategies. It assigns a numerical rating based on direct CO₂ emission factors such as energy efficiency and indirect factors like sample storage, transportation, waste management, and reagent use. By implementing CaFRI, laboratories can optimize resource use, minimize environmental hazards, ensure compliance with eco-friendly regulations, and target specific areas for improvement. Case studies using techniques such as spectrophotometry for polidocanol in ampoules, dispersive solid phase microextraction with HPLC/UV for ritonavir in human plasma, carbon quantum dots for molnupiravir in capsules, and homogenous liquid-liquid microextraction with HPLC/UV for favipiravir in human plasma demonstrated CaFRI’s applicability in evaluating the carbon footprint across diverse analytical methods and matrices. These case studies illustrated that energy consumption and CO₂ emissions are key criteria for CaFRI scores, with higher scores indicating more sustainable methods.

Proposal of a general theory of greenness, connecting all chemical disciplines and not only; the description of basic concepts and relationships.