EN 1149-3 vs EN 1149-5: Understanding Antistatic Testing

EN 1149 is the European test series for electrostatic properties of protective clothing. Buyers often quote "EN 1149" as if it were a single requirement, but the parts measure different things and serve different roles. Here is how they fit together.

The test parts: what each one measures

• EN 1149-1 — surface resistivity. Measures how easily charge travels across the fabric surface, in ohms (per square). A low value means charge can move away instead of accumulating. Some fabrics with isolated conductive threads pass -3 but not -1, which is why the two methods coexist.
• EN 1149-2 — vertical resistance. Measures resistance through the fabric thickness, from one face to the other. Rarely a standalone requirement, but relevant to how a garment bleeds charge to earth.
• EN 1149-3 — charge decay. Measures how quickly a charged fabric dissipates charge, expressed as a decay half-time. This suits grid-type constructions where the conductive threads are not continuous across the surface.
• EN 1149-4 — garment-level test. A test method for complete garments on a mannequin.

The requirement part: EN 1149-5

EN 1149-5 is not a test method — it is the performance and design requirement that antistatic garments must meet. For materials, it requires passing either EN 1149-1 (surface resistivity below a defined threshold) or EN 1149-3 (decay time below a defined threshold). On design, it requires that the garment includes a groundable element and covers the ignition-risk areas — for example, sleeves and jacket fronts must not be able to ride up and expose untreated clothing underneath.

What this means when buying fabric

1. Ask which test part the fabric was tested to — a report quoting only "EN 1149" without a part number says nothing.
2. Ask for the actual values (resistivity in ohms, decay half-time in seconds), not just pass/fail.
3. Remember that EN 1149-5 compliance is assessed for the garment design as well as the material. Fabric data supports garment certification; it is not a substitute for it.
4. For FR/AS combined fabrics, check that the antistatic result was measured after the specified laundering cycles, not only on new fabric.

This article summarises the general structure of the standard for buying decisions. For formal compliance work, always work from the current published editions of the standards and your certifier's guidance.