BS EN ISO 20471 Standard | Arc Flash & Protective Clothing Standards

Published 09 Sep 2021

Arc Flash & Protective Clothing Standards

BS EN ISO 20471 Standard Arc Flash & Protective Clothing Standards

BS EN ISO 20471

Arc Flash & Protective Clothing Standards

BS EN ISO 20471 is the European Standard for High Visibility Protective Clothing – High Visibility Clothing. Test methods and requirements.

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 It has replaced EN 471 which has now been withdrawn.


BS EN ISO 20471 standard’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.

View further information about Arc Flash Clothing Standards.

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 50mm 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.

BS EN ISO 20471 | Standard Overview

Protective clothing. High visibility clothing. Test methods and requirements.

ISO 20471:2013 specifies requirements for high visibility clothing which is capable of visually signalling the user’s presence. The high visibility clothing is intended to provide conspicuity of the wearer in any light condition when viewed by operators of vehicles or other mechanized equipment during daylight conditions and under illumination of headlights in the dark.

Performance requirements are included for colour and retroreflection as well as for the minimum areas and for the placement of the materials in protective clothing.

This British Standard is the UK implementation of EN ISO 20471:2013+A1:2016. It is identical to ISO 20471:2013, incorporating amendment 1:2016. It supersedes BS EN ISO 20471:2013 which is withdrawn.

The UK committee voted against the approval of this standard. The reason for this objection is that several UK experts expressed the opinion that the inclusion of the Water Vapour Resistance (clause 5.6.3) is a general requirement and not specific to High Visibility Clothing. This may discriminate against a range of materials currently in use resulting in serious implications for  manufacturers of garments to this standard.

Standard Status | Current, Under Review

Published | 2013

➡ Standards | RIS-3279-TOM | IEC 61482-2 | BS EN ISO 11611BS EN 1149-5 | BS EN ISO 14116 | BS EN ISO 11612 | BS EN 13034 | BS EN 342 | BS EN 14404 | BS EN 343 | HSG47

BS EN 471:2003+A1:2007

High-visibility warning clothing for professional use. Test methods and requirements.

BS EN 471:1994

Specification for high-visibility warning clothing.

BS 6629:1985

Specification for optical performance of high-visibility garments and accessories for use on the highway.

Clothing & Garments

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