Overview
ISO 17491-2:2012 - Protective clothing - Test methods for clothing providing protection against chemicals - Part 2: Determination of resistance to inward leakage of aerosols and gases (inward leakage test) specifies laboratory procedures to evaluate the integrity of complete chemical protective suits against inward leakage. The standard defines two complementary challenge methods: Method 1 (NaCl aerosol) to simulate aerosol challenges and Method 2 (SF6 gas) to simulate gaseous challenges. Tests are performed under dynamic conditions using human subjects to assess leakage particularly in the breathing zone.
Key topics and technical requirements
- Two test methods
- Method 1: sodium chloride (NaCl) aerosol challenge with specified particle size distribution (0.02 µm to 2 µm; mass median ≈ 0.6 µm) and target chamber concentration as defined in the standard.
- Method 2: sulfur hexafluoride (SF6) gas challenge; accurate detection range ~0.001% to ~20% and recommended test atmosphere ≈ 0.1% SF6 by volume.
- Test setup and apparatus
- Enclosed challenge chamber surrounding the suited subject, treadmill for dynamic movement, atomizer/collison aerosol generator, detectors (flame photometer for NaCl, SF6 detector), manometer for pressure, sampling probe positioned inside the suit (breathing zone).
- Procedure essentials
- Continuous flow of challenge agent around the suit and sampling of internal suit air; maintain manufacturer’s minimum design airflow or provide equivalent breathing-air supply.
- Two suit samples tested; each suit tested on two qualified human subjects.
- Human-subject requirements
- Subjects familiar with the equipment, medically assessed fit for testing, fitted according to manufacturer instructions; selection in line with national regulations.
- Measured outcome
- Quantitative inward leakage values for aerosols/gases, evaluating suit integrity (seams, interfaces, closures, assemblies) under realistic movement.
Applications and users
- Intended for use by:
- PPE manufacturers validating whole-suit integrity during design and quality control
- Independent test laboratories performing conformity and certification testing
- Occupational safety professionals, procurement officers and regulators specifying protective clothing for chemical, industrial, emergency response and hazardous-material operations
- Practical uses:
- Verifying breathing-zone protection and leak paths in gas-tight and non-gas-tight suits
- Comparing suit designs, materials, and assemblages under dynamic conditions
- Supporting selection of appropriate chemical protective clothing for specific exposure scenarios
Related standards
Keywords: ISO 17491-2:2012, inward leakage test, protective clothing, chemical protective suit, NaCl aerosol, SF6 gas, breathing zone, suit integrity, PPE testing.