The BS EN ISO 20471 standard specifies the requirements for clothing designed to increase the wearer’s visibility in order to make them more noticeable in hazardous situations during the day and at night (illumination in car headlights). It has replaced EN 471 which has now been withdrawn.
THE CONTENTS OF THIS EN STANDARD
BS EN ISO 20471’s icon is a safety vest placed adjacent to a number which represents the design classification of the garment. The classification is 1, 2 or 3 where Class 1 provides the minimal level of visibility and class 3 provides the highest level prescribed by the standard.
THE CLASSIFICATION
The classification is derived from the number of square metres of fluorescent fabric and the number of square metres of reflective strip incorporated in a garment.
| Material | Class 3 garments | Class 2 garments | Class 1 garments |
| Background material | 0,80 | 0,50 | 0,14 |
| Retroflective material | 0,20 | 0,13 | 0,10 |
| Combined performance material | n.a. | n.a. | 0,20 |
NOTE – The clothing class is determined by the lowest area of visible material
EN ISO 20471 provides the following guidance on risk factors and selection of clothing:
| Risk Level | Factors related to the risk level (Vehicle speed/Type of road user) | Risk Level |
| High risk ISO 20471 class 3 | >60km/h / Passive | High Visibility – Day and night visibility – 360 Degrees (visibility from all sides) – Design for form recognition – Encircling the torso (Class 2 & 3) – Quantity and quality for day and night |
| High risk ISO 20471 class 2 | ≤60km/h / Passive | |
| High risk ISO 20471 class 1 | ≤30km/h / Passive |
The fluorescent fabric must encircle the torso, sleeves and trouser legs with at least 40% or the minimum required area of fluorescent material present on the front of the garment ( and on the back of the garment). The reflective strips must be 50 mm wide and the space between 2 reflective strips must be at least 50 mm. The distance from ‘the end’ of the garment (e.g. the end of a trouser leg) to the reflective strip must also be at least 50mm. Reflective strips can be positioned in a variety of different ways; Class 3 garments must cover the wearers torso and have either reflective strips about the sleeves or full length trouser legs.
What is EN ISO 20471:2013?
Certified and approved garments for protection when the user needs visually to signal his or her presence to vehicles in daylight, at night or in poor weather conditions.
High visibility clothing has a fluorescent surface and retroreflective material that meet certification requirements in three different classes. Class 3 is the highest safety class. The performance class can be obtained using a single garment or a clothing assemble, e.g. jacket and trousers. This will be stated on CE-label. A class 3 garment shall cover the torso and shall have either sleeves with retroreflective bands or full-length trouser legs with retroreflective bands. ​​​​​​​
Understanding the performance classes
This standard categorises hi-vis garments into 3 classes and all garments should be labelled with the EN ISO 20471 icon, accompanied by the appropriate class number. You can see an example of how this would look below:
The selection and use of hi-vis should always be based on a risk assessment of the conditions and risks for a particular worker. The class of hi-vis workwear you need depends on the risk zone the worker is in, which in turn determines the amount of reflective tape and fluorescent material required.
Certification is based on the surface area of both types of material, and sets out minimum requirements for each:
| Class 1 | Class 2 | Class 3 | |
| Reflective Tape | 0.10 sqm | 0.13 sqm | 0.20 sqm |
| Fluorescent Material | 0.14 sqm | 0.50 sqm | 0.80 sqm |
Class 1: Lowest level of visibility
Items that commonly meet class 1 include hi-vis trousers when worn separately from other hi-vis garments.
Class 2: Intermediate level of visibility
Items that commonly meet class 2 include hi-vis sleeveless vests.
Class 3:Â Highest level of visibility
Items that commonly meet class 3 are hi-vis jackets and sleeved hi-vis vests. Class 3 can be achieved in 2 ways:
1. By wearing an individual garment rated as class 3
2. By wearing jointly certified products that makeup class 3 based on the total area of fluorescent and reflective material
The 3 components of hi-vis clothing
EN ISO 20471 covers the design and performance requirements of each element of a hi-vis garment.
The 3 main components are:
1. The fluorescent material
This especially boosts visibility during daylight hours but can also increase visibility at night.
2. The reflective strips
Designed for visibility during the darker hours, reflective stripes require a light source to work and create retro-reflection. Essential for those working at night.
There are different types of reflective strip, the most common being ‘glass beads reflective’. These need to be handled correctly to retain the functionality of the garment.
3. The contrast material
This is darker coloured parts of the garment that are less sensitive to dirt than the fluorescent material and reflective strips, without which the functionality of some hi-vis garments would diminish. The areas covered with the contrast fabric tend to be where dirt is most likely to build up, for example, the sleeves, ankles, across the abdomen, and knees.
Key requirements of EN ISO 20471
The standard covers the requirements for the base fabric colour, minimum areas for reflectivity, and placement of tape.
The requirements on the minimum area of reflective material (detailed in the table below) can restrict the ability to adjust garments. For example, shortening trousers might reduce the area of fluorescent material too much. This also means that hi-vis trousers shouldn’t be tucked into boots when in use, as the garment may no longer comply. The same goes for wearing any clothing that obscures or covers the fluorescent material, for example wearing a non-hi-vis jacket over a hi-vis vest.
Three colours of fluorescent material are approved in the standard; yellow, orange and red. In addition to the surface area of each material, there are also requirements for the performance of these materials, as well as the degree of reflection from the reflective strips. Physical properties including tensile strength, thermal resistance, and dimensional stability are also covered within the standard to ensure that all hi-vis is suitable for a range of working conditions where there is a high risk.
There are strict requirements on the amount of ‘bleeding’ between the reflective strips and the fluorescent and contrast materials. This bleeding refers to the residues of colour within the material that can stain the sensitive parts of the hi-vis garment. As the fluorescent material is always a bright colour, it can be affected by the darker colour of the contrast material. EN ISO 20471 stipulates the tolerated level of bleeding to ensure the fluorescence is still effective.
Although branding PPE is a great way of promoting and distinguishing your company on site, employers should take care when adding logos to hi-vis workwear. This is because the areas of background or retro-reflective material that is covered will be excluded from the calculation of the required minimum area. Where possible, aim to place logos on the contrast material so visibility is not impacted.
How is EN ISO 20471 different from EN471?
When EN ISO 20471 replaced EN471 in 2013, several improvements were made to the standard. The new standard makes a stronger distinction between the different types of risk situations, which hi-vis users can then apply to their own situation to determine the level of protection they require.
Crucially, the requirements now depend on which part of the body the garment is covering, rather than the type of garment as in EN471. There are five options within this: torso only; torso and arms; legs; torso and legs; and torso, arms, and legs.
Although there are still 3 classes that hi-vis can be categorised into, the requirements of class 3 have increased. Class 3 garments must now cover the torso and either comprises of full-length sleeves or trousers.
If a sleeve obscures part of a reflective band on the torso of a garment, a band must be added to the sleeves. For hi-vis garments with short sleeves, if the sleeve obscures a torso band of retro-reflective tape, the standard now dictates that there must also be a band of retro-reflective tape about the sleeves.
Interestingly, the tensile strength, burst strength and tear strength requirements on fabrics were reduced, whereas colour fastness was upgraded to a minimum of grade 4. The EN ISO 20471 logo is an updated version, designed to be clearer with just one figure next to illustration, which tells you the class of the garment.