Flame Retardant Workwear: When It's Required and What to Look For
If you work in an environment with heat, flame, or electrical arc hazards, standard cotton workwear won't cut it. A single spark landing on untreated fabric can keep burning, spreading, and causing severe burns before you even register what's happened.
Flame retardant (FR) workwear is designed to do the opposite. It self-extinguishes when the flame source is removed. It doesn't melt onto your skin. And in some industries, wearing it isn't just good practice, it's a legal requirement.
This guide covers when FR workwear is actually mandatory, what the ratings mean, and how to pick the right gear for your team.
When is flame retardant workwear a legal requirement?
There's no single regulation that says "you must wear FR clothing." Instead, several pieces of legislation create that duty depending on your work environment.
**DSEAR 2002** (Dangerous Substances and Explosive Atmospheres Regulations) is the big one. If your workplace has flammable gases, vapours, or combustible dusts, your risk assessment must address ignition sources. That includes your clothing. A static discharge from a synthetic tee shirt can ignite a flammable atmosphere: it's happened.
**The Electricity at Work Regulations 1989** covers anyone working on or near live electrical equipment. Where there's risk of arc flash, non-FR clothing can catch fire or melt onto the skin. The regulations require suitable PPE, which in practice means arc-rated clothing to EN 61482-2.
**COSHH** kicks in for welding fumes, molten metal, and hot processes. If your risk assessment identifies burns or fire as a hazard, you need to control it. FR workwear is the standard control measure.
**PUWER** applies to welding equipment and other hot-work tools. It requires adequate training and PPE for the task.
And then there's the **PPE at Work Regulations 2022**. Even after the recent changes, the core duty remains: where risks can't be controlled by other means, suitable PPE must be provided. That's the catch-all that catches most people.
So when do you actually need FR workwear? Realistically: welding, electrical utility work, oil and gas, chemical processing, foundries, glass manufacturing, and any environment with flammable dusts (grain mills, wood processing, metal powder work). If you're not sure, your fire risk assessment should tell you.
EN ISO 11612: the main standard for heat and flame
EN ISO 11612 is the standard you'll see on most flame retardant workwear sold in the UK. It covers protective clothing against heat and flame, not just firefighting kit, but industrial FR garments for everyday use like trousers, coveralls, and jackets.
The standard tests several things:
**Limited flame spread (A1, A2).** The fabric is held over a flame for a set time. After the flame is removed, it should not continue burning beyond a certain point. No afterflame, no afterglow that spreads. This is the basic test: everything FR should pass A1 or A2.
**Convective heat (B).** This measures how well the fabric insulates against direct flame heat. Rated B1 through B6. Higher numbers mean better protection. For most welding and foundry work, B1 or B2 is sufficient. B3 and above is for more intense heat exposure.
**Radiant heat (C).** Measures protection against radiated heat (like standing near a furnace). C1 through C4. If workers are near hot surfaces or molten materials, you want this.
**Molten metal splash.** Two separate tests: D for molten aluminium and E for molten iron. Each is rated 1 through 3. This matters in foundries and metalworking.
**Contact heat (F).** If workers might press against hot surfaces. F1 through F3.
Most industrial FR garments carry a combination of these ratings. A typical welding coverall might be marked A1, B1, C1, E1. That tells you it will self-extinguish, provide basic convective and radiant heat protection, and resist iron splash.
Inherent FR vs treated fabrics
There are two ways to make FR workwear, and the difference matters for how long it lasts.
**Inherent FR fabrics** (like Lenzing FR, Kermel, or Aramid blends) have flame retardant properties built into the fibre itself. The protection can't wash out or wear off. It costs more upfront, but the garments typically last longer and require less careful washing. These are common in high-risk industries like oil and gas.
**Treated FR fabrics** (like Proban or Pyrovatex cotton) start with a base fabric (usually 100% cotton) that's chemically treated to make it flame retardant. These are cheaper and comfortable, but the treatment can degrade over time with repeated washing. You need to follow the care label strictly. No bleach, no fabric softener. The wrong detergent can strip the FR treatment without any visible change to the garment.
Which is better? Inherent FR lasts longer and needs less fuss. Treated FR is more affordable and often more breathable. For occasional use (visitor coveralls or infrequent hot work), treated is fine. For daily use in high-risk environments, inherent FR pays for itself over the life of the garment.
What about arc flash? That's a different standard
Arc flash protection uses EN 61482-2, not EN ISO 11612. They're related but not interchangeable.
An arc flash generates an explosive blast of heat and pressure. The clothing needs to withstand that specific energy profile. EN 61482-2 tests for Arc Thermal Performance Value (ATPV) or Energy Limit (ELIM), rated in cal/cm².
Some fabrics carry both EN ISO 11612 and EN 61482-2 certification. If your team does both hot work and electrical work, those dual-cert garments are the sensible choice.
What to look for when buying FR workwear
**Check the certification label.** Every FR garment sold in the UK should have a permanent label showing the standard, the performance levels, and the care instructions. If it doesn't, don't buy it.
**Consider the layering.** Most FR protection relies on the fabric trapping an insulating layer of air. Tight clothing reduces that gap. Garments should be loose fitting but not baggy; you don't want snagging hazards either.
**Think about the whole outfit.** FR trousers with a standard cotton t-shirt doesn't make sense. The t-shirt can catch fire and negate the trousers. If the risk assessment calls for FR, it usually calls for full-body coverage.
**Don't forget comfort.** If the workwear is uncomfortable, people won't wear it properly. Or they'll roll up sleeves, unbutton collars, and defeat the protection. Modern FR fabrics are much more breathable than the old stiff canvas. Try before you buy a full set.
**Check the washing instructions.** This is the biggest hidden cost. FR workwear often needs industrial laundering or very specific home washing. Factor that into the budget. Some suppliers offer rental and laundry services that take care of this.
Common mistakes we see
We deal with a lot of customers at Colbrook who are new to FR workwear. A few things come up again and again.
People buy FR coveralls but wear non-FR layers underneath. A polyester t-shirt under an FR coverall will melt if the outer layer burns through. Every layer worn with FR should be FR or natural fibre (cotton, wool). No synthetics next to the skin.
People assume FR means fireproof. It doesn't. FR clothing is designed to self-extinguish and limit burn injury. It won't let you walk through flames. Treat it as a last line of defence, not a free pass.
People forget that FR protection has a lifespan. Inherent FR lasts the life of the garment. Treated FR may need replacing after a certain number of washes; check the manufacturer's guidance. And any garment with visible damage, heavy soiling, or chemical contamination should be replaced.
People don't train their teams. A worker who doesn't know why they're wearing FR clothing is more likely to mistreat it, wash it wrong, or skip wearing it. Five minutes of explanation saves months of wasted PPE.
**Need help selecting FR workwear for your team?** Call us on **+44(0)1236 755544** or browse our [FR workwear range](https://www.colbrook.co.uk/shop). We supply Scotland and the rest of the UK with certified flame retardant clothing from Portwest, Helly Hansen, and other trusted brands. We can advise on the right standard for your risk assessment.
