Hi-Vis Clothing Standards Explained: EN ISO 20471, Chapter 8 & Rail Spec RIS-3279-TOM
Choosing the wrong high-visibility workwear doesn't just fail an audit — it can cost a life. This guide covers exactly what EN ISO 20471 requires for Class 1, 2 and 3 hi-vis, what Chapter 8 of the Traffic Signs Manual demands from every operative on the public highway, and why anyone working on the UK rail network needs orange RIS-3279-TOM certified clothing — not just standard hi-vis.
What is EN ISO 20471?
EN ISO 20471 is the European and international standard governing high-visibility clothing used in professional environments. It specifies the minimum surface areas of fluorescent background material and retroreflective material a garment must contain to receive certification, alongside requirements for design and 360° visibility coverage in all conditions.
The standard requires that compliant garments make the wearer visible in daylight, at twilight, and at night. It achieves this through two distinct materials working in combination:
Retroreflective material — reflects light from an external source (such as vehicle headlights) directly back towards that source, making the wearer conspicuous to drivers in low-light and night-time conditions.
EN ISO 20471 replaced the older EN 471 standard and is the recognised benchmark for hi-vis PPE compliance across most industries in the UK and EU. However, highway workers and rail workers face additional mandatory requirements that sit on top of the base standard — detailed in full below.
Class 1, 2 and 3 hi-vis: what each class requires
EN ISO 20471 divides certified garments into three classes based on the total minimum surface area of fluorescent and retroreflective material present. The higher the class number, the greater the coverage and the more hazardous the environment the garment is designed for.
Class 3 garments must cover the full outline of the wearer's body — the jacket must have long sleeves, or the wearer must combine a certified Class 2 jacket with certified Class 2 hi-vis trousers. This full-outline rule exists so plant operators and vehicle drivers can clearly distinguish a worker's silhouette in adverse weather or low-light conditions.
Browse our EN ISO 20471 certified hi-vis clothing range — Class 1, 2 and 3 garments available with in-house embroidery and full compliance documentation.
Chapter 8: hi-vis requirements for highway workers
Chapter 8 refers to Chapter 8 of the Department for Transport's Traffic Signs Manual, formally titled Traffic Safety Measures and Signs for Road Works and Temporary Situations. It sets the complete safety framework for all temporary traffic management on UK public roads — including the mandatory PPE requirements for every operative on the highway.
Who does Chapter 8 apply to?
Chapter 8 applies to every operative working on or near the public highway: road maintenance crews, utilities workers, telecoms engineers, traffic management operatives, street works contractors, and anyone carrying out carriageway or footway works. If your team sets foot on the public highway as part of their role, Chapter 8 PPE requirements apply to every person on site.
Hi-vis class requirements under Chapter 8
Chapter 8 sets specific EN ISO 20471 class requirements based on the type of road being worked on:
| Road type | Minimum hi-vis class required |
|---|---|
| Urban roads, residential streets, rural roads | EN ISO 20471 Class 2 |
| Motorways and high-speed dual carriageways | EN ISO 20471 Class 3 |
Chapter 8 also requires that all vehicles stopped on the highway display retroreflective red and yellow chevron markings on their rear-facing surface. Procurement managers responsible for Chapter 8 compliance typically manage both clothing and vehicle marking requirements.
Need Chapter 8 compliant hi-vis and PPE for your highway operatives? View our workwear range or browse our full PPE collection, all supplied with compliance documentation.
Rail spec: RIS-3279-TOM and Network Rail's full orange policy
The UK rail industry operates its own mandatory high-visibility specification that goes significantly beyond EN ISO 20471. The standard is RIS-3279-TOM (formerly GO/RT 3279), published by the Rail Safety and Standards Board (RSSB). It applies to anyone working on or near the line — maintenance crews, trackside engineers, inspectors, and all contractors working lineside on the UK rail network.
Why orange — not yellow?
EN ISO 20471 permits fluorescent yellow-green, orange-red, and red. RIS-3279-TOM specifies fluorescent orange only. Orange provides improved contrast against both rural and urban environments and — critically — avoids confusion with yellow and green colours used in railway signalling systems. Train drivers are trained to identify orange as a trackside worker. The permitted colour is precisely defined: chromaticity coordinates X: 0.588, Y: 0.371 with a minimum luminance factor of 0.4.
Key RIS-3279-TOM requirements
Colour: Fluorescent orange only. Yellow hi-vis is not permitted anywhere on the UK rail network, regardless of EN ISO 20471 class rating.
Coverage: Retroreflective tape must be present on the front, back, and sides of every garment, outlining the wearer's body shape from all viewing angles.
Anti-entanglement: Pull-apart (breakaway) waistcoats are required where entanglement with passing trains is a hazard. These are engineered to break away cleanly if snagged, rather than pulling the wearer towards the train.
Network Rail full orange policy: Network Rail requires all individuals on or near the line to be fully dressed in fluorescent orange — jacket, trousers, and any additional layers. A single orange vest over non-compliant clothing does not satisfy this policy.
BAS 1 Group supplies RIS-3279-TOM certified rail workwear and PPE with in-house embroidery to your branding. Visit our rail and transport sector page for compliant garments and managed supply options.
Combining garments to achieve a higher class
EN ISO 20471 permits garment combinations to reach a higher class — but only under controlled conditions. Each individual garment in the combination must be independently certified to EN ISO 20471. The combined fluorescent and retroreflective surface areas of both garments together must meet the minimum for the target class.
The most common example is a certified Class 2 jacket worn with certified Class 2 hi-vis trousers to achieve the full-body coverage required for Class 3 environments. A Class 2 jacket worn over uncertified work trousers does not constitute a valid Class 3 combination.
Branding and embroidery on hi-vis: what's permitted
Branded and embroidered hi-vis clothing is standard practice across construction, utilities, FM, rail, and traffic management — and it is fully permitted under EN ISO 20471, provided that any logo, embroidery, or print does not reduce the visible fluorescent surface area below the minimum required for the garment's certified class.
Where embroidery or a printed logo covers part of the fluorescent fabric, that area is no longer counted towards the certified minimum. If the coverage takes the garment below the class threshold, the garment is no longer compliant at that class. This is a common failure point when hi-vis is decorated by suppliers unfamiliar with the standard.
Need branded, compliant hi-vis for your site team? View our in-house embroidery service or get in touch to discuss your requirements.
Need compliant hi-vis for your team?
BAS 1 Group supplies EN ISO 20471, Chapter 8 and RIS-3279-TOM compliant hi-vis clothing with in-house embroidery and full compliance documentation. ISO 9001, 14001 and 45001 certified — serving construction, rail, utilities, FM and highways sectors across the UK since 2000.
Shop hi-vis range Get a quoteFrequently asked questions
Is EN ISO 20471 a legal requirement in the UK?
There is no single piece of UK legislation that names EN ISO 20471 by number. However, the Health and Safety at Work etc. Act 1974 and the Personal Protective Equipment at Work Regulations 1992 require employers to provide suitable PPE wherever a risk assessment identifies the need. EN ISO 20471 is the recognised standard against which hi-vis clothing is assessed in this context. For highway work, Chapter 8 specifies compliance by class. For rail, RIS-3279-TOM compliance is contractually mandated by Network Rail and train operating companies.
Can yellow hi-vis be worn on the railway?
No. RIS-3279-TOM specifies fluorescent orange only for all trackside workers. Network Rail's full orange policy requires the entire outfit — jacket, trousers, and any additional layers — to be certified fluorescent orange. Yellow hi-vis is not compliant on the UK rail network regardless of its EN ISO 20471 class rating.
What class of hi-vis is required on a motorway?
Chapter 8 requires EN ISO 20471 Class 3 for all operatives working on motorways and high-speed dual carriageways. The garment or garment combination must provide at least 0.80 m² of fluorescent material and 0.20 m² of retroreflective material, and must cover the full outline of the body including the torso and either long sleeves or full-length trouser legs with retroreflective bands.
Does adding a logo to hi-vis invalidate its certification?
Not automatically. Embroidery or printing on fluorescent fabric reduces the visible fluorescent surface area. If the reduction takes the garment below the minimum for its certified class, the garment is no longer compliant at that class. A supplier with in-house embroidery capability will calculate this before decorating and confirm compliance in writing — always request this documentation.
What does RIS-3279-TOM mean?
RIS-3279-TOM stands for Railway Industry Standard 3279, Train Operations and Maintenance. Published by the Rail Safety and Standards Board (RSSB), it defines the minimum requirements for high-visibility clothing worn by anyone working on or near the UK rail network. It superseded the earlier GO/RT 3279 specification and requires garments to be fluorescent orange and meet at least EN ISO 20471 Class 2 as a baseline.
Can two Class 2 garments count as Class 3?
Yes — under EN ISO 20471, provided both garments are independently certified and the combined fluorescent and retroreflective surface areas meet the Class 3 minimums. Both must be worn simultaneously for the combination to apply. For rail environments, each garment must also independently satisfy RIS-3279-TOM requirements.
Where can I buy compliant hi-vis workwear in the UK?
BAS 1 Group supplies EN ISO 20471 Class 1, 2 and 3 hi-vis garments alongside RIS-3279-TOM certified rail spec clothing from our facility in Rainham, Essex. All garments are available with in-house embroidery and can be supplied with full compliance documentation. Browse our hi-vis range or request a quote.
