Hi-Vis Clothing Standards:
EN ISO 20471 Explained

What is EN ISO 20471?

EN ISO 20471 is the international standard that governs high-visibility clothing in the UK and across Europe. It sets out exactly what a compliant hi-vis garment must look like — how bright the fluorescent material needs to be, how reflective the tape must perform, and how much of each is required to keep a worker visible in hazardous conditions.

The standard replaced the older EN 471 in 2013. If you still have hi-vis garments certified under EN 471, those certificates expired five years after issue — meaning anything made to the old standard is no longer considered compliant for use as formal PPE.

One thing that often surprises people is that EN ISO 20471 isn't really about the garment in isolation — it's about the wearer. The standard defines minimum visible areas on the person's body, so compliance depends on how the garment is worn, not just what it looks like on a hanger. A pair of hi-vis trousers worn under a coat, for example, won't provide compliant coverage if the reflective bands are hidden.

To be sold or supplied in the UK, hi-vis garments used as PPE must carry either a UKCA mark (for the UK market post-Brexit) or a CE mark. Both indicate the product has been tested against EN ISO 20471 by an accredited laboratory. A supplier should be able to provide a Declaration of Conformity on request — if they can't, that's worth taking seriously.

The three classes: 1, 2 and 3

EN ISO 20471 divides hi-vis garments into three classes based on how much fluorescent background material and retroreflective tape they contain. The higher the class number, the more visible the wearer — and the higher the risk environment it's designed for.

Combining garments to achieve Class 3

You don't always need a single Class 3 garment. EN ISO 20471 allows two separate compliant items to be combined to achieve Class 3 coverage as a set. A common approach is to pair a Class 2 jacket (product group B on the label) with Class 2 compliant hi-vis trousers (product group X or Y). Together, the combination meets Class 3 requirements.

Minimum material requirements

Every compliant garment needs two types of material working together. Understanding what each does helps make sense of why the minimums are set where they are.

Fluorescent background material is the bright yellow, orange-red or red fabric that makes a worker visible in daylight and at dusk. It works by absorbing UV light and re-emitting it as visible light — which is why it appears almost luminous against darker backgrounds like tarmac, vegetation or machinery.

Retroreflective tape is the silver banding that reflects light back directly towards its source. At night, when vehicle headlights hit retroreflective tape, the bands appear as bright to the driver as the headlights themselves — immediately identifying the worker's outline. The tape is what makes hi-vis effective in darkness; the fluorescent fabric alone does not perform well in low light.

The standard also specifies where the retroreflective bands must be placed, not just how much there is. For Class 3, bands must encircle the torso horizontally and also run along the sleeves or trouser legs — ensuring the wearer's outline is recognisable from any angle.

Which industries and roles need what class

The right class for any given job comes down to the risk assessment. But across most industries, certain patterns are well established. The table below gives a useful starting point — though it shouldn't replace a site-specific assessment, particularly in complex or mixed-risk environments.

One thing worth being clear on: site rules often set a higher minimum than the standard itself requires. Always check the specific site requirements before specifying garments, particularly on large civil engineering or infrastructure projects.

Employer duties and legal responsibilities

Under the Personal Protective Equipment at Work Regulations 2022, employers have clear duties around PPE — including hi-vis workwear. Getting them wrong can result in improvement notices, prosecution, and — more importantly — a serious injury that was preventable.

• Carry out a suitable risk assessment to identify where hi-vis PPE is needed
• Select PPE that is appropriate for the risk identified — the class must match the exposure
• Ensure garments are properly CE or UKCA marked and meet EN ISO 20471
• Provide the PPE free of charge to employees
• Maintain PPE in good working order — this includes laundering and replacing worn garments
• Provide adequate information and training so workers know how to wear garments correctly
• Ensure PPE is stored appropriately when not in use

Branded and printed hi-vis — what you need to know

Adding a company logo or printed name to hi-vis workwear is completely legitimate — and it's something Colbrook does every day. But there are rules, and ignoring them can make an otherwise compliant garment non-compliant.

The standard requires minimum areas of both fluorescent background material and retroreflective tape. Any printing or embroidery applied to the garment can reduce the effective area of those materials. If the branding covers enough fluorescent fabric, the garment may drop below the minimum threshold for its declared class.

• Logos and text should be placed on the fluorescent background areas with care — positioning matters
• Do not print over retroreflective tape; this will degrade its reflective performance
• Dark-coloured ink on fluorescent fabric reduces the effective luminance — lighter inks perform better
• Some garments have specific zones reserved for decoration; check the product specification
• Discuss placement with your supplier before ordering — it's much easier to solve at the design stage

How to check a garment is compliant

Non-compliant hi-vis is more common than it should be, and the consequences of an incident involving a garment that didn't meet the standard are serious. Here's what to check before it gets near your workforce.

• The EN ISO 20471 logo with the correct class number (1, 2 or 3) clearly displayed on the label
• A UKCA mark (for UK supply) or CE mark
• Clear washing and care instructions — a compliant garment will always have these
• The product group letter (A, B, C, D or E) — this tells you how to combine garments for higher class ratings
• Maximum wash cycles, where the manufacturer has specified them

Any reputable workwear supplier should be able to provide a Declaration of Conformity for their EN ISO 20471 products. Ask for it. It's also worth checking whether your supplier is a BSIF Registered Supplier — the British Safety Industry Federation audits its registered suppliers and checks that the PPE they sell genuinely meets the standards it claims to meet.

Care, washing and when to replace

A hi-vis garment that was fully compliant on the day it was issued can become non-compliant over time through use, washing and exposure. Many organisations don't have clear processes around this — and it's an area that's easy to overlook.

Washing guidance

• Always follow the care label — temperature limits must not be exceeded
• Do not wash hi-vis garments with other clothing, particularly dark or heavy items
• Avoid bleach, stain removers or alkaline detergents — these damage both fluorescent fabric and reflective tape
• Do not tumble dry — heat degrades reflective tape performance over time
• Allow garments to dry naturally in a ventilated space, away from direct sunlight and direct heat
• Inspect garments after each wash for signs of fading, tape peeling or fabric contamination

When to replace

Most guidance suggests hi-vis workwear should be replaced every 6 to 12 months depending on frequency of use and washing. Many garments are rated for a maximum of around 25 wash cycles. Retire a garment when:

• The fluorescent fabric has visibly faded or is greying rather than appearing bright
• Retroreflective tape is peeling, cracked or has lost its reflective surface
• The fabric has been contaminated with oil, paint or grease that cannot be washed out
• It has been repaired in a way that reduces the compliant area of material
• It has reached the manufacturer's stated maximum wash count

Railway standard: RIS-3279-TOM

For anyone working on or near railway lines in the UK, EN ISO 20471 alone is not sufficient. The rail industry operates under RIS-3279-TOM — which sits on top of EN ISO 20471 and introduces stricter specifications for rail environments.

RIS-3279-TOM requires high-visibility orange background fabric specifically, and sets a higher minimum for the concentration of that orange material. It also requires retroreflective tape with a minimum reflectivity reading of 330 cd/lx/m². A standard yellow EN ISO 20471 Class 3 jacket does not satisfy railway requirements, regardless of its class.

Frequently asked questions