ISO 29903-1:2020

Overview

ISO 29903-1:2020 - Comparison of toxic gas data from different tests - Part 1: Guidance and requirements provides principles and a standardized methodology for characterizing and comparing toxic gas measurements obtained in laboratory fire tests of different sizes and types. The standard focuses on how to interpret, compare and (where appropriate) predict toxic gas data between bench-scale, intermediate- and large-scale fire tests, taking into account key factors that influence results such as combustion conditions, sampling strategy and analytical technique. It is intended as guidance for comparing measured gas yields and concentrations, not for assessing effluent toxicity itself.

Key Topics and Requirements

• Scope and intent

  • Defines relevance and significance of toxic gas data for comparing tests and predicting scale-up/scale-down results.
  • Applies principally to the gases listed in ISO 13571: CO2, CO, hydrogen halides (HCl, HBr, HF), SO2, HCN, NO/NO2, formaldehyde and acrolein.
  • Explicitly not intended for toxicity characterization of effluents.

• Combustion and test specimen factors

  • Requires documentation of combustion conditions (thermal environment, ventilation, flame persistence) and specimen characteristics that affect gas production.

• Toxic gas data expressions

  • Discusses yields, concentrations, production rates, total releases, and contributions to FED/FEC metrics used in fire safety assessment.

• Measurement quality

  • Emphasizes measurement uncertainty and limit of detection (LoD) as critical to establishing similarity or difference between datasets.
  • Combined uncertainty is a primary factor in assessing agreement between tests.

• Comparison and prediction methodology

  • Provides principles for comparing stages of fire, CO/CO2 ratios, equivalence ratio and other combustion indicators.
  • Outlines steps for assessment of available data, comparison procedures and evaluation of agreement, plus prediction from one model scale to another.

• Documentation

  • Requires clear record of test configuration, sampling strategy, analysis methods and uncertainty estimates to support comparison.

Practical Applications and Who Uses It

• Fire safety engineers and researchers comparing bench-scale and full-scale test results.
• Laboratories conducting fire effluent sampling and gas analysis.
• Product manufacturers and testing bodies seeking to validate small-scale tests for hazard assessment.
• Regulators and consultants performing fire hazard/risk assessments who require reproducible, defensible comparisons of toxic gas data.
• Useful when establishing whether small-scale test data can predict real-scale gas emissions for design, compliance or safety modelling.

Related Standards

• ISO 13571 (life‑threatening components of fire)
• ISO 19703 (generation and analysis of toxic gases)
• ISO 5725‑1 (measurement accuracy and precision)
• ISO 16312‑1, ISO 16730‑1, ISO 19706 and ISO 13943 - referenced for model validity, verification, fire threat guidance and vocabulary.

Keywords: ISO 29903-1:2020, toxic gas data, fire tests, bench-scale, large-scale, measurement uncertainty, toxic gas yields, combustion conditions, sampling strategy, fire safety.