An 8-step procedure-specific risk framework enables reproducible biosafety level assignment beyond agent-based...

Current biosafety frameworks that directly link Risk Group (RG) to Biosafety Level (BSL) fail to capture how much exposure varies across the procedures performed in modern biomedical laboratories operating with genetically modified organisms, viral vectors, and multi-step protocols. This article presents the Procedure-Specific Risk (PSR) framework, an 8-step operational protocol for reproducible Biosafety Level assignment in which the exposure generated by the procedure-rather than agent taxonomy-serves as the primary determinant of containment.

A structured comparative analysis of ten national and international biosafety reference documents was conducted (WHO Laboratory Biosafety Manual 4th ed., BMBL 6th ed., CDC Biological Risk Assessment 2024, INSST Technical Guide 2024, and relevant EU and Spanish legislation). Conceptual convergence was evaluated through qualitative thematic synthesis. The resulting 8-step protocol integrates agent Risk Group classification, procedural exposure characterization, and modulating factor evaluation into a BSL assignment matrix, and is supported by a structured assessment template and a freely accessible bilingual digital implementation tool.

Framework validation rests on three complementary forms of evidence: content validity (all components derived from the ten analyzed regulatory sources), convergent validity (PSR-derived BSL assignments consistent with WHO and BMBL recommendations across all six case studies), and coverage validity (purposive case selection spanning RG1-3, Low-High PSR, escalation and reduction scenarios, and dual-technology comparison). Prospective multi-institutional inter-rater reliability assessment (target κ ≥ 0.60) constitutes the planned next validation step, supported by the digital implementation tool.

The PSR framework provides a structured, reproducible, and immediately applicable protocol for proportionate containment in bioengineering and biotechnology settings. It is compatible with existing institutional biosafety programs and requires no structural regulatory modification for adoption. Implementation is supported by a freely accessible bilingual web tool, a structured assessment template, and six worked examples covering RG1-3 agents and diverse procedural risk levels.