ISO 374-4:2019

Overview

ISO 374-4:2019 - "Protective gloves against dangerous chemicals and micro‑organisms - Part 4: Determination of resistance to degradation by chemicals" - specifies a laboratory test method to determine how glove materials degrade when the outside surface has continuous contact with a liquid chemical. The method quantifies degradation by measuring the change in puncture resistance after exposure and provides reporting requirements and informative annexes (interlaboratory results and an alternative weight‑change test).

Key topics and technical requirements

• Scope: Measures material degradation caused by continuous contact with challenge chemicals; intended for natural and synthetic polymer gloves. Lined gloves may be impractical to test if the liner cannot be separated.
• Sampling: Three gloves; condition at (23 ± 2) °C and (50 ± 5) % RH for ≥24 h. Cut six 20 mm specimens per glove (18 total): three exposed and three unexposed control specimens per glove.
• Apparatus (high level): 20 ml crimp top vials, 20 mm cutting dies and septa, punched sample holder, dynamometer with puncture stylus per ISO 23388:2018, and vial support.
• Test conditions and procedure: Conduct at (23 ± 2) °C. Place ~2 ml challenge chemical in vials, seal specimens over septa and invert to expose the external surface; one‑hour exposure (±5 min). Puncture tests are performed with the dynamometer at 100 mm/min to record peak puncture force.
• Results calculation: Degradation (%) for each glove sample is calculated from the average puncture forces of exposed vs unexposed specimens (formulae provided in the standard). The overall degradation for the material is the mean of the three samples; report the standard deviation.
• Observations & reporting: Document manufacturer reference, glove material/lot, chemical identity and concentration, DR1/DR2/DR3 and DR mean, SD, liner separation status, physical changes (swelling, brittleness, hardening, colour change, delamination), and any deviations from the method.

Applications and users

• Who uses it: PPE test laboratories, glove manufacturers (R&D and quality assurance), occupational safety managers, procurement specialists, and regulators assessing glove suitability for chemical handling.
• Practical value: Helps determine material compatibility under continuous exposure, supports glove selection for chemical processes, verifies manufacturing consistency, and complements permeation and penetration tests (ISO 374‑4 indicates these additional tests are preferable because degradation alone does not fully describe protective performance).

Related standards

• ISO 374‑1 - Terminology and performance requirements for chemical risks
• ISO 21420 - General requirements and test methods for protective gloves
• ISO 23388:2018 - Puncture stylus and related puncture test requirements

Keywords: ISO 374-4:2019, protective gloves, chemical resistance, degradation test, puncture resistance, continuous contact, glove materials, PPE testing.