Hi-vis clothing is one of the most recognisable forms of PPE, and one of the most important. Whether you're working roadside, on a construction site, in a warehouse with moving vehicles or out in poor weather, being seen is your first line of defence against being struck.

This guide covers how hi-vis works, what the EN ISO 20471 classes mean, what UK employers must provide and how to keep garments effective.

How does hi-vis clothing work?

Hi-vis garments work in two ways. Fluorescent material, typically yellow or orange, reacts with the ultraviolet in daylight to appear brighter than ordinary colours, so the wearer stands out at dawn, at dusk and in dull weather.

Retroreflective tape bounces light, such as vehicle headlights, straight back to its source. That keeps you visible to drivers in darkness and low light, when fluorescent colour on its own does little. Good hi-vis uses both, with tape placed around the torso, arms and legs so the wearer's shape is recognisable as a person.

Colour matters too. Yellow is the most common choice, while orange is required on UK rail infrastructure.

Hi-vis classes under EN ISO 20471

In the UK and Europe, hi-vis clothing is certified to EN ISO 20471, which grades garments into three classes based on the amount of fluorescent and reflective material they contain.

• Class 1 offers the lowest level of visibility. Some hi-vis trousers worn on their own fall into this class, and it suits low-risk areas away from traffic.
• Class 2 is the intermediate level, often seen in the classic hi-vis vest or waistcoat.
• Class 3 is the highest level. Garments must cover the torso and have either sleeves with retroreflective bands or full-length trouser legs with bands, so jackets, coveralls and suits are typical.

For motorways and high-speed roads, Class 3 is generally expected and is often a client or site rule. UK rail is different: the rail industry standard RIS-3279-TOM requires orange hi-vis meeting at least Class 2. Always check your client's or principal contractor's site rules. Our guide to hi-vis classes 1, 2 and 3 goes into more detail.

What employers must provide

Under the PPE at Work Regulations 1992, employers must provide suitable hi-vis clothing free of charge wherever a risk assessment identifies the need. Since 6 April 2022 this duty also extends to limb (b) workers, which covers most casual and agency-type staff.

Suitable means more than the right class. Garments should fit over the layers being worn, suit the weather and not create new hazards, such as loose fabric near moving machinery. Workers should keep garments clean, undamaged and correctly fastened, since an open jacket or vest hides much of the reflective tape.

Keeping hi-vis effective

Faded or dirty hi-vis loses effectiveness, so inspect it regularly and replace it when it no longer looks bright. Warning signs include dull or patchy fluorescent fabric, tape that is cracked, peeling or missing, and stains that won't wash out.

Check the garment label as well. Many hi-vis items state a maximum number of wash cycles, and beyond that the garment may no longer meet its class. Wash inside out, skip fabric softener and keep the iron away from the tape. Our guide on how to wash workwear has more care tips.

In winter, layering matters. A Class 3 hi-vis jacket worn over a fleece keeps the protection on the outside, where it counts, rather than buried under an ordinary coat.

Quick answers

Is hi-vis a legal requirement?

There's no blanket law requiring hi-vis for everyone, but where a risk assessment identifies a need, employers must provide suitable hi-vis free of charge under the PPE at Work Regulations. Clients and sites may also set their own rules.

What colour hi-vis is required on the railway?

UK rail requires orange hi-vis meeting at least Class 2 under RIS-3279-TOM. Check the specific requirements with your principal contractor before starting work.

When should hi-vis clothing be replaced?

Replace hi-vis when the fluorescent fabric has faded, the reflective tape is cracked or peeling, it's badly stained or damaged, or it has passed the maximum wash cycles shown on the label.

From vests and t-shirts to jackets and trousers, our hi-vis clothing range covers every season and job role, and many items can carry your company logo. Contact us if you need help choosing the right class.