GUIDE TO FLAME RESISTANT CLOTHING

TO THE EN ISO 11612 & RELATED STANDARDS

Flame resistant (FR) clothing is designed to protect workers from exposure to heat, flames, and thermal hazards. Unlike flame-retardant treatments, which may wash out over time, flame resistant fabrics are either inherently resistant or engineered to maintain their protective qualities throughout the life of the garment.

The EN ISO 11612 standard defines the performance requirements for protective clothing against heat and flame. Depending on the workplace, other standards such as EN ISO 11611 (welding), IEC 61482 (arc flash), or EN 1149 (anti-static) may also apply.

Identifying the Hazard and Risk

When selecting FR clothing, the first step is a proper risk assessment:

Task — Are you welding, working with open flames, exposed to molten metal, or at risk of electrical arc flash?
Hazard — Is the primary risk direct flame contact, radiant heat, molten splash, or an arc event?
Risk — What is the likelihood of exposure and the severity of potential injury?

The principal hazard should always take priority. For example, if arc flash is the greatest risk, arc-rated garments to IEC 61482 must be selected even if other hazards are present.

EN ISO 11612: Protection Levels

The EN ISO 11612 standard specifies several test methods and performance classes. A garment certified to EN ISO 11612 must protect against at least one type of heat exposure.

Here are the key codes and their meanings:

Code	Type of Protection	Performance Levels	Description
A1 / A2	Limited Flame Spread	Pass / Fail	Protects against ignition when exposed to a small flame (A1 = surface ignition, A2 = edge ignition).
B	Convective Heat	1–3	Resistance to heat transfer from flames.
C	Radiant Heat	1–4	Resistance to heat from radiant sources such as furnaces.
D	Molten Aluminium Splash	1–3	Resistance to molten aluminium splash.
E	Molten Iron Splash	1–3	Resistance to molten iron splash.
F	Contact Heat	1–3	Resistance to heat transfer by direct contact with hot objects (up to 250°C).

Other Relevant Standards

Depending on your work environment, you may also need to consider:

EN ISO 11611 — Welding and allied processes (Class 1 = lower risk, Class 2 = higher risk).
IEC 61482-2 — Protection against arc flash (arc thermal performance value / energy breakopen threshold).
EN 1149-5 — Electrostatic properties, preventing sparks in flammable atmospheres.
EN 343 — If working outdoors in rain, combining FR protection with waterproof breathability.

Selecting the Right FR Garment

When choosing FR clothing, consider:

Work activity — Welding, foundry work, petrochemical work, electrical maintenance.
Fabric type — Inherent FR fibres (e.g. aramid, modacrylic) vs treated cotton blends.
Garment design — Coverage, layering, closures, and comfort.
Compatibility — FR clothing must not compromise the performance of other PPE such as hi-vis, rainwear, or harnesses.

Care and Maintenance

Always follow manufacturer washing instructions to preserve protective properties.
Do not use bleach or fabric softeners, as these may reduce flame resistance.
Inspect garments regularly for damage, wear, or contamination with flammable substances (oil/grease).
Replace garments immediately if their integrity is compromised.