Originally published: 9 March 2026
Last reviewed for compliance: 9 March 2026
Hi-vis clothing is required at work where a workplace risk assessment identifies that workers must be clearly visible to reduce the risk of injury from moving vehicles, plant, machinery, poor lighting, adverse weather, or other visibility hazards.
In the UK, this most commonly applies across construction, logistics, warehousing, highways, rail, utilities, and public-facing maintenance environments.
This guide explains:
- When hi-vis clothing is required at work in the UK
- How risk assessments determine the need for hi-vis PPE
- Which environments commonly require high-visibility clothing
- When EN ISO 20471 applies
- How to choose the right garment type and class
This article is written for Health & Safety managers, compliance teams, procurement professionals, site managers and employers responsible for PPE selection.
When is hi-vis clothing required at work?
Hi-vis clothing is required when a workplace risk assessment identifies that workers need to be seen clearly in order to reduce risk. This usually means there is a danger from moving vehicles, mobile plant, machinery, low-light conditions, poor weather, or complex visual backgrounds.
Hi-vis should be selected as a risk control measure, not simply because it is standard site clothing.
Where hi-vis clothing is being used as PPE, it should normally be suitable for the environment and, where required, compliant with EN ISO 20471.
š Read our full guide: EN ISO 20471 Explained: Hi-Vis Classes, Requirements & Employer Responsibilities (UK)
What determines whether hi-vis is required?
The requirement for hi-vis clothing should come from a workplace risk assessment. Employers should consider whether workers need to be visible from a distance and from multiple angles in order to avoid incidents.
Typical factors include:
- Exposure to moving vehicles or plant
- Traffic speed and stopping distance
- Poor natural or artificial lighting
- Bad weather such as rain, fog or low winter light
- Background clutter that makes workers harder to spot
- Whether the task is near loading bays, roads, yards or vehicle routes
- Whether workers need to be visible during night operations
Which workplaces commonly require hi-vis clothing?
Hi-vis is commonly required in workplaces where visibility is a key part of site safety. The exact garment type and class will depend on the level of risk.
- Construction sites ā active plant, deliveries, changing light conditions and mixed pedestrian/vehicle zones
- Warehousing and logistics ā forklifts, loading bays, distribution yards and depot traffic
- Roadworks and highways ā traffic exposure, roadside work and high-risk visibility conditions
- Rail infrastructure ā trackside work and specialist sector requirements
- Utilities and public services ā roadside or public-facing maintenance and repair work
- Facilities and external maintenance ā car parks, service roads and mixed-access environments
Is hi-vis always legally required in the UK?
No. UK law does not say that every worker must always wear hi-vis clothing. Instead, employers are required to assess risks and provide suitable PPE where needed.
If visibility is necessary to control risk, then hi-vis becomes part of that PPE requirement.
Where hi-vis is identified as necessary PPE, employers must provide suitable garments free of charge, ensure they are maintained, and replace them when they are no longer fit for purpose.
When does EN ISO 20471 apply?
EN ISO 20471 is the main standard for high-visibility clothing used in hazardous work environments. If hi-vis is required as PPE, garments should usually meet this standard.
EN ISO 20471 covers:
- Fluorescent background materials
- Retroreflective tape
- Garment design and visible surface area
- Class designation based on visibility level
š Read more: EN ISO 20471 Explained
How do you know which hi-vis class is required?
Once a risk assessment shows that hi-vis is needed, the next step is choosing the correct class. Higher-risk environments usually require higher visibility coverage.
The class depends on:
- The speed and type of vehicle hazard
- How far away workers need to be seen
- Lighting and weather conditions
- The complexity of the working environment
- Whether the role involves roadside, trackside or night operations
š Read our full guide: Hi Vis Classes Explained: Class 1, Class 2 & Class 3 (UK)
Examples of when hi-vis is usually required
- Working around forklifts in a warehouse or depot
- Operating on a construction site with active plant
- Carrying out roadside repairs or traffic management duties
- Working outdoors in poor light or bad weather
- Undertaking rail or infrastructure maintenance
- Moving through loading bays or reversing areas
Common mistakes
Even where hi-vis is supplied, mistakes can still lead to poor compliance or poor protection.
- Using non-certified garments ā bright clothing is not automatically compliant PPE
- Choosing the wrong class ā a low-risk garment may be unsuitable for higher-risk work
- Ignoring garment condition ā faded or damaged garments may no longer be effective
- Branding over critical visibility areas ā logos should not reduce reflective or fluorescent coverage where compliance matters
š Related guide: Workwear Logo Placement Guide
What about branded hi-vis clothing?
Branded hi-vis clothing can still be compliant, but logo placement must be handled carefully. Printing or embroidery should not interfere with reflective bands or reduce visible fluorescent areas below required thresholds.
Useful related reading:
- Workwear Logo Placement Guide
- Print vs Embroidery: Which Branding Method Is Right for Your Workwear?
Choosing the right hi-vis clothing
To choose the right hi-vis clothing for work:
- Start with a formal risk assessment
- Confirm whether hi-vis is required
- Determine the right class for the environment
- Choose garments suited to the task and conditions
- Check any site, rail or traffic-management-specific rules
- Ensure garments are maintained and replaced when needed
š Browse compliant garments: Hi-Vis Workwear
Frequently asked questions
Is hi-vis clothing legally required at work in the UK?
It is required where a workplace risk assessment identifies that workers must be visible to reduce risk. Employers must then provide suitable PPE, which may include hi-vis clothing.
Does every construction site require hi-vis?
Many construction sites do require hi-vis because of plant, deliveries and changing visibility conditions, but the exact requirement depends on the site rules and risk assessment.
Does hi-vis clothing need to be EN ISO 20471 compliant?
Where hi-vis is being used as PPE to control workplace risk, garments should normally meet EN ISO 20471.
How do I know which hi-vis class I need?
The correct class depends on the risk assessment, traffic speed, lighting conditions and environment. See our guide: Hi Vis Classes Explained.
Where can I read more about the standard?
Read our full guide here: EN ISO 20471 Explained.