ISO 16900-2:2017

Overview

ISO 16900-2:2017 - "Respiratory protective devices - Methods of test and test equipment - Part 2: Determination of breathing resistance" specifies standardized test methods to measure breathing resistance for complete respiratory protective devices (RPDs), filters for RPDs, and respiratory interfaces (RI). The standard defines both static and dynamic measurement methods, required equipment, test conditions, reporting requirements and guidance on measurement uncertainty.

Key topics and requirements

• Scope: Test methods for breathing resistance of RPDs, filters and RIs.
• Two methods:
  • Method 1 - Static breathing resistance: constant airflow drawn through a filter or RI; pressure drop (Δp) measured across the device and corrected for the support system.
  • Method 2 - Dynamic breathing resistance: RPD mounted on a headform/torso and connected to a breathing machine; peak inhalation/exhalation pressures measured during realistic breathing waveforms.
• Equipment: calibrated pressure gauges, flowmeters (corrected to ambient conditions), regulated blowers or suction sources, breathing machine (for dynamic tests), and appropriate supports/headforms (per ISO 16900-5).
• Procedures: mount device leak‑tight, measure pressure drop with and without the device on the support, calculate device resistance as the difference. For RIs with valves, measure in multiple orientations (upright, up, down, left side, right side).
• Environmental and accuracy requirements: ambient testing conditions nominally 16–32 °C and (50 ± 30) % RH; values not stated as maxima/minima have ±5% tolerance; flow rates corrected to standard conditions (1 013 hPa, 20 °C); temperature accuracy ±1 °C.
• Reporting: include test parameters (number of specimens, support types, conditioning, flow rates), measured breathing resistances, note that flow rates are corrected to 1 013 hPa and 20 °C, and provide an estimate of measurement uncertainty (Annex A).

Applications and who uses it

ISO 16900-2:2017 is used by:

• RPD manufacturers to validate filter and mask breathing resistance during development and production.
• Test laboratories to perform standardized breathing resistance tests and produce comparable test reports.
• Regulatory bodies and certification organizations to assess compliance with performance standards that reference breathing resistance requirements.
• Health & safety professionals and procurement teams seeking objective data on respirator breathing effort for user comfort and acceptance.

Practical applications include designing low-resistance filters, verifying valve performance, and ensuring occupational respirators meet ergonomic and safety performance criteria.

Related standards

• ISO 16900-5 (breathing machine, headforms and torso)
• ISO 16972 (terms, definitions and units)
• ISO 16900-10 (resistance to ignition and heat) These referenced documents define support equipment, terminology and complementary test methods used together with ISO 16900-2:2017.