ISO 6942:2022

Overview

ISO 6942:2022 specifies standardized test methods for evaluating materials and material assemblies used in protective clothing against radiant heat. The standard defines two complementary procedures - Method A (visual assessment) and Method B (quantitative evaluation) - to determine how single- or multi-layer textiles and other clothing materials behave when exposed to a controlled source of radiant heat. Results are intended to classify materials for heat-protective applications but are limited by testing at room temperature and therefore must be interpreted alongside other criteria for final garment suitability.

Key Topics

• Two test methods
  • Method A: Visual assessment of changes in appearance (shrinkage, charring, discoloration, melting, glowing).
  • Method B: Measurement of protective effect using a calorimeter to record times for temperature rises (t12 and t24) and calculation of radiant heat transfer index (RHTI) and heat transmission factor (TF).
• Apparatus and setup
  • Radiant source: Six silicon carbide (SiC) heating rods arranged and powered to reach ≈1 100 °C.
  • Specimen holder and test frame sized for free-standing samples or assemblies.
  • Calorimeter and temperature recorder for Method B.
• Test conditions and calibration
  • Conditioning and testing atmospheres, specified heat flux density selection, and calibration of the radiant source are required for reproducible results.
• Sampling and reporting
  • Procedures for representative specimens, measurement precision (Annex A), and required test-report contents are provided.
• Limitations
  • Tests are performed at room temperature; results do not necessarily predict behaviour at elevated ambient temperatures.

Applications

• Used by PPE manufacturers, material suppliers, and independent testing laboratories to classify fabrics and multi-layer assemblies for jobs involving radiant heat exposure (industrial operations, firefighting, foundry work).
• Supports product development, quality control, regulatory compliance and specification of materials for heat-protective garments.
• Useful input for risk assessment when combined with other standards, real-world exposure data and garment system testing.

Related Standards

• ISO 6942:2022 references vocabulary and terminology such as ISO/TR 11610. It should be used alongside other protective clothing and PPE standards and national regulations when determining final garment performance and certification.

Keywords: ISO 6942:2022, protective clothing, radiant heat testing, Method A, Method B, calorimeter, heat flux density, RHTI, heat transmission factor, PPE testing labs.