ISA TR84.00.07:2018

Guidance on the Evaluation of Fire, Combustible Gas, and Toxic Gas System Effectiveness, provides comprehensive guidance on evaluating the effectiveness of fire, combustible gas and toxic gas systems (FGSs) in process industries. It integrates performance-based design principles that are consistent with functional safety standards ANSI/ISA-84.00.01 and IEC 61511 to help assess detector coverage, system availability and mitigation action effectiveness for FGS functions aimed at reducing risk from hazardous releases.
This technical report contrasts prescriptive and performance-based approaches, emphasizing quantitative and semi-quantitative risk analysis methods to establish performance targets, verify detector placement and evaluate mitigation strategies. It includes detailed methodologies for hazard identification, consequence and frequency analysis and system design verification within a safety lifecycle framework.
Annexes provide example techniques for target selection, detector coverage assessment, mitigation effectiveness evaluation and practical application examples illustrating fire detection and suppression, combustible and toxic gas detection and the use of computational fluid dynamics for indoor gas detection design. This report is intended as an informative resource to supplement existing engineering practices and support improved, risk-informed FGS designs tailored to specific operational environments.