High Visibility Clothing, the Standards Explained
ISO 20471 specifies the requirements for high visibility clothing, intended to improve the conspicuity of the wearer in areas where the risk of not being seen is high; such as working on roads, on or near a rail track, on airports or seaports.
A conforming high visibility garments is made up of background material (fluorescent fabric) to provide daytime visibility and retroreflective material (reflective tape) for night-time conspicuity. There are three colours permitted as background material within the standard; fluorescent yellow, fluorescent orange and fluorescent red. These are specified in terms of their luminance and chromaticity co-ordinates.
Retroreflective technologies return a cone of light back towards the source from which it came (such as the headlights on a car); this can be achieved through glass bead technology or prismatic reflective tape technologies.
There are three classes within the standard, class 1, 2 or 3; class 3 offering the highest level of protection and class 1 the lowest. The class of a garment (or ensemble of garments) is defined by the amount of background material and the amount of retroreflective material on a garment. The minimum amounts are defined as follows:
The standard sets out a specific design criterion for garments to conform; for example, a class 3 garment must cover the torso and have sleeves with reflective bands and/or trouser legs with reflective bands.
Class 2 + 1 = 3?
ISO 20471 class 3 can be obtained by combining the classes of the upper and lower garment, such as a class 2 anorak with a class 1 trouser, providing the two garments meet the minimum requirements for class 3 when worn together.
Most companies will apply a company logo or job-role related text to a garment before it is issued. For a garment to still conform to ISO 20471 once a badge has been applied, the remaining exposed background material must at least meet the minimum requirements specified for that class.
User information and labelling
Garments must be marked and labelled in line with ISO 13688 which specifies the general requirements for protective clothing. This will show information on the manufacturer and the garment’s performance, sizing and product code. A user information sheet will include information on how to wash and store the garments as well as any warnings of misuse.
All requirements of the standard must be certified by a notified body in order for a certificate to be issued.
The Traffic Signs Manual
In the UK, the Traffic Signs Manual adds that clothing for those working on motorways or high speed roads must conform to ISO 20471 class 3 and that jackets or coveralls must have full length sleeves, two reflective bands encircling the body and two encircling the sleeves with two reflective braces over the shoulders. “The requirement may be varied to three-quarter-length sleeves where a risk assessment shows full length sleeves would present increased risk due to the activity being undertaken”. Those working on motorways and high-speed roads should also wear high visibility trousers complying to ISO 20471 class 1 “where the carrying of large items of equipment or other activities may at any time obscure the visibility of the high visibility jacket.”