EN 20471 is an international safety standard that ensures high-visibility clothing makes the wearer clearly visible when working in dangerous or poorly lit environments. Garments must undergo vigorous testing methods and meet key requirements to receive EN 20471 certification.
The EN ISO 20471 standard
EN ISO 20471, also known as EN 20471, is an international standard for high-visibility clothing. This safety standard specifies requirements for high-visibility clothing that is capable of visually signalling the wearer’s presence. EN ISO 20471 certified garments ensure the wearer is clearly visible from all angles and when working in hazardous environments or low-light conditions.
EN 20471:2013
EN ISO 20471:2013 for high-visibility clothing was released in 2013. This updated safety standard replaced the former EN 471 standard to align with international standards, update requirements and testing methods, expand the scope, and introduce an improved classification system.
As safety certificates are only valid for five years, this revision means that any garments made to the former EN 471 certification are no longer compliant. Any current hi-vis clothing should comply with the new EN ISO 20471 standard.
The EN 20471 standard states key requirements for background materials, retroreflective materials, and combined performance materials which are categorised into three classes. This standard is crucial for ensuring the safety of workers who are exposed to low-visibility conditions such as construction workers, road maintenance crew, or workers undertaking nighttime operations.
There are three classes for EN 20471 compliant garments. This class denotes the visibility level of the garment, allowing the worker to choose garments with a visibility level that best suits their working conditions.
Class 1 is applied to garments that have the lowest level of visibility, Class 2 is for clothing with an intermediate level of visibility, and Class 3 garments have the highest level of visibility. The class for EN ISO 20471 clothing can be found on the garment label.
EN 20471 components of hi-vis clothing
There are three main components of EN ISO 20471 that regulate the design and performance of each element of clothing.
Fluorescent material
Fluorescent material can be defined as material that emits light after absorbing electromagnetic radiation such as visible or ultraviolet (UV) light. While this definition sounds scientific it simply means that the material enhances the wearer’s visibility in daylight.
Fluorescent material is brightly coloured, ensuring it stands out against most surroundings and easily be seen for increased safety. The three approved colours in the EN 20471 standard are yellow, orange, and red.
Reflective strips
Reflective strips, also known as retroreflection tape, work by projecting light back to the source. When this happens, the strip appears to light up, ensuring the wearer can easily be seen.
By featuring reflective strips, EN 20471 certified garments increase the wearer’s visibility at night or in low-light conditions by reflecting light back to its source, such as vehicle headlights.
Contrast material
Many hi-vis garments are made with darker coloured materials to contrast the lighter fluorescent fabric and reflective strips. These darker contrasting elements can better withstand dirt than fluorescent material or reflective strips, improving the functionality of the garments.
Due to their ability to withstand dirt, these areas are usually placed in areas where dirt can build up, such as on knees, shoulders, or pockets.
EN 20471 testing methods
EN ISO 20471:2013 uses vigorous testing methods to ensure compliant garments are able to withstand the environments in which they are intended to be worn.
Colour fastness
It is crucial that high-visibility clothing does not lose its colour or fade over time. Colour fastness testing assesses the resistance of a material to change any of its colour characteristics, including the colour transferring to other materials.
Hi-vis garments are tested for colour fastness in a number of ways including assessing the fabric’s ability to withstand sunlight exposure using a Xenon arc lamp and testing colourfastness with washing and dry cleaning solutions.
Colour measurement
As mentioned earlier, there are three colours used for EN 20471 complaint garments: yellow, orange, and red.
These colours are tested using spectrophotometer measurement under specific conditions. This test assesses how much light is absorbed or transmitted by the material to identify the garment colour and fluorescence.
Dimensional stability
Dimensional stability testing ensures that EN ISO 20471 certified clothing offers an adequate level of performance during their usage.
This test helps determine whether the garment has good “recovery properties” by subjecting the material to a cycle of drying, washing, and drying again. At each stage, the fabric’s dimensions in the warp and weft are measured.
Tape testing
The reflective strips of hi-vis clothing are assessed using a photometer to measure the amount of light reflected back to the original light source. This test determines how light is reflected from the reflective strips at various distances and angles.
Garment assessment
The design of a garment can also impact its visibility. To ensure compliance with EN ISO 20471, a garment assessment is carried out to determine whether specific design requirements are present, such as tape placement and spacing.
The garment assessment is performed to confirm whether the clothing article is compliant with EN ISO 20471 requirements for high visibility.
Chemistry testing
As the garments are intended to be worn by someone, it is important that the materials used within this personal protective equipment (PPE) does not contain any harmful chemicals. This is a requirement for any PPE clothing, as per the PPE Directive.
Chemical testing is carried out to ensure the garment does not contain any chemicals that may be harmful to the wearer.
EN 20471 requirements
EN ISO 20471:2017 standard features key requirements for the base fabric colour, minimum areas of reflectivity, and tape placement for high-visibility clothing.
The requirements for the minimum area of reflective material may restrict the wearer’s ability to adjust garments. For example, hi-vis trousers should not be tucked into safety boots. Doing so would render the garment as no longer complying with the standard.
There are also requirements for the surface area of each material and the performance of these materials, including the degree of reflection for the reflective strips. Physical requirements such as tensile strength, thermal resistance, and dimensional stability all ensure the hi-vis clothing is suitable for a variety of high-risk work environments.
Another requirement of EN 20471 covers the tolerated amount of “bleeding” between reflective strips and the fluorescent and contrast materials. By specifying the tolerance for “bleeding”, EN 20471 ensures that the fluorescent and reflective elements of the garment remain effective.
While many employers will want to add branding to their hi-vis garments, it is crucial that personalisation does not interfere with the garment’s performance. EN 20471 sets requirements for adding personalisation to high-visibility clothing. Any area of background or retro-reflective material that is covered with branding will be excluded from the calculated required minimum area.
