ISO 13571:2012

Overview

ISO 13571:2012 - Life‑threatening components of fire provides guidelines to estimate the time to compromised tenability in fires. It is a tool for fire safety engineering used alongside fire-growth, smoke movement, chemical-species and people‑movement models. The standard focuses on the consequences of human exposure to life‑threatening fire components (fire‑effluent toxicity, heat and smoke obscuration) and gives a structured methodology to estimate when occupants’ ability to perform cognitive and motor tasks becomes compromised.

Key topics and technical requirements

• Time‑to‑compromised‑tenability concept: the earliest occurrence among four endpoints - asphyxiant gas effects, irritant gas effects, heat/radiant exposure, and smoke visual obscuration.
• Toxic‑gas model: treats asphyxiant toxicants and irritant toxicants separately. Uses Fractional Effective Dose (FED) for asphyxiants (integrated concentration‑time) and Fractional Effective Concentration (FEC) for irritants to estimate exposure over discrete time increments.
• Mass‑loss model: simplified approach for cases with unknown effluent composition; uses total fire‑effluent toxic potency (e.g., ISO 13344 laboratory outputs) to compute FEDs.
• Heat and radiant energy model: analogous FED approach to evaluate thermal compromise of tenability.
• Smoke‑obscuration model: based on minimum detectable contrast; assesses when smoke density impairs navigation and orientation.
• Assumptions & exclusions: models assume independent action of insults, moderate activity, normal ambient conditions and do not address particulate/aerosol interactions or long‑term health sequelae.
• Reporting & uncertainty: users must document inputs, model choices and quantify uncertainties inherent in predictions.

Practical applications and users

ISO 13571 is intended for practical application in:

• Fire safety engineering and risk assessment - integrating with CFD and fire growth models to estimate occupant tenability timelines.
• Evacuation and rescue planning - determining available escape and rescue times, including for immobile occupants.
• Building design and smoke control - informing layout, detection, alarm and smoke management strategies.
• Product fire hazard evaluation and regulatory compliance - as an input to holistic fire risk analyses (not as a standalone product test). Primary users include fire safety engineers, CFD modelers, building code officials, emergency planners, forensic analysts and manufacturers involved in fire performance assessment.

Related standards

• ISO 13943 - Fire safety vocabulary
• ISO 13344 - Methods for total fire‑effluent lethal potency (referenced for mass‑loss model)
• ISO/TR 13387 and ISO/TR 16738 - guidance on people movement and fire modelling context

Keywords: ISO 13571, compromised tenability, fire safety engineering, toxic‑gas model, mass‑loss model, smoke obscuration, time to compromised tenability, fire effluent toxicity.