EN ISO 20471 Explained - Hi-vis Clothing Standard
Hi-vis workwear is a crucial requirement in industries where a significant proportion of the work occurs near traffic, cranes or other motorised vehicles, as well as work at night. The main role of hi-vis clothing is to distinguish the wearer from the background with the result being that they are clearly visible from all angles, preventing accidents occurring in potentially dangerous situations. As hi-vis plays such a vital role in the safety of workers in these industries, it's important that these garments, including vests, trousers, jackets, and polo shirts, have EN ISO 20471 certification.
What is EN ISO 20471?
ISO 20471:2013 High Visibility Clothing is an international standard for the safety requirements and test methods of hi-vis workwear and is applicable to high-risk situations. It specifies requirements for 'high visibility clothing which is capable of visually signalling the user's presence' and assesses the suitability and durability of retro-reflective materials.
EN ISO 20471 was released in 2013, replacing EN 471:2003 A1:2007. As certificates are only valid for 5 years, this means that the last garments made to EN471 certification will lose compliance by the end of 2018. Any new hi-vis workwear garments made after 2013 must be CE marked and designed to comply with the new standard.
Just as in EN471, the requirements for background materials, retroreflective materials, and combined performance materials are categorised into 3 classes. There are some important differences to note, which we will cover later in the article.
The 3 components of hi-vis clothing
EN ISO 20471 covers the design and performance requirements of each element of a hi-vis garment. There are usually 3 main components:
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.
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: 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 can be achieved in 2 ways:
1. By wearing an individual garment rated as class 3
2. By wearing jointly certified products that make up class 3 based on the total area of fluorescent and reflective material
You can identify when products are jointly certified by looking on the inner label where the joint article will be stated.
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 comprise 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.
Maintaining compliance with EN ISO 20471
Whilst EN ISO 20471 details test methods and requirements before use, it doesn't cover the requirements of remaining compliant after the garment has been worn. However, it's important to check and maintain hi-vis workwear to ensure its performance isn't compromised over time.
Most hi-vis products only have a maximum life of 25 washes, unless stated otherwise on the label. This means that over-cleaning can lead you to lose compliance. Wearing over-washed hi-vis increases the likelihood of an accident, however, not washing regularly enough can also impact the performance as stains and dirt will decrease visibility.
Because of this, it's best to have at least 2 hi-vis garments for each part of the body, and rotate their use so that you can prolong their life and wash less often. With this method, you should aim to replace hi-vis garments approximately every 3 months.
There are ways of extending the life of workwear and PPE, but when a hi-vis product is no longer capable of performing to its certified class, it's time to replace it.