Selecting arc-rated PPE

Arc-rated PPE and the applicable standards in the UK.

Introduction

If arc-rated Personal Protective Equipment (PPE) is identified as an arc flash mitigation measure then it is important that the PPE is selected appropriately, taking into account the needs of the wearer, the environment in which it will be used, and relevant standards. In the United Kingdom, the supply and use of PPE must be in compliance with the requirements of the Personal Protective Equipment at Work Regulations 1992 as amended by the Personal Protective Equipment at Work (Amendment) Regulations 2022.

The UK's Health and Safety Executive have a website that covers the major topics, as well as a freely available guide to the regulations.

Arc-rated PPE Requirements

When it comes to the arc flash hazard specifically, the two most important things to check any clothing product for are:

  1. Is the item UKCA (or CE) marked?
  2. Has the item been rated in accordance with IEC 61482-2?

This information will be available in various places including product labelling and product datasheets, typically available on websites or directly from suppliers. An example label showing this information is reproduced below.

Arc flash label from an item of PPE showing the UKCA marking and the 61482-2 ratings
Above: an example label for an item of arc-rated PPE showing its UKCA/CE marking and the ratings according to IEC 61482-2

UKCA (or CE) marking ensures that the product complies with all applicable safety standards, not just those specifically for arc flash.

Compliance with IEC 61482-2 demonstrates that the product has undergone testing specifically aimed at determining its ability to protect the wearer from the thermal effects (i.e. heat energy) of an arc flash. Depending on exactly what testing was completed, a product may have an Arc Rating (either ELIM and/or ATPV or EBT50) or an Arc Protection Class (either APC 1 or APC 2), or in many cases, a combination of these. In order to be compliant with IEC 61482-2 and display a conformance mark then the item must have one or more of the following:

  • An ELIM value of at least 3.2 cal/cm2
  • An ATPV or EBT50 value of at least 4 cal/cm2
  • APC 1

The terms ELIM, ATPV, EBT50 and APC are defined in detail below.

Arc-rated PPE Selection

Ideally, selection of arc-rated PPE should be informed by the results of an Arc Flash Study. Depending on the methodology used this will tell you either:

  • the prospective incident energy at an item of electrical equipment (e.g. if following IEEE 1584) allowing you to select PPE by its Arc Rating.
  • the minimum applicable APC (e.g. if following DGUV-I 203-077) allowing you to select PPE by its Arc Protection Class.
Flow chart showing how arc-rated PPE is selected by determining the requirement and then selecting PPE rated according to the appropriate test method
Above: how arc-rated PPE can be selected depending on whether you are selecting based on Arc Rating or Arc Protection Class

IEC 61482-2: Requirements

The latest UK version of this standard is BS EN 61482-2:2020.

This specifies the requirements for material and garments intended to be worn to protect electrical workers against the thermal hazards of an electric arc. It also defines two different test methods which each result in different ratings for arc-rated PPE. These two methods are described in more detail below.

Note: IEC 61482-2 specially applies to arc-rated clothing. Protection of eyes, face, head, hands and feet against the electrical arc hazard is covered elsewhere.

IEC 61482-1-1: Open Arc Test Method

The latest UK version of this standard is BS EN IEC 61482-1-1:2019.

This is a test method for determing the arc rating value(s) of material and clothing. It is commonly known as the open arc test method. It is the more versatile of the two test methods.

Test Process

In the open arc test fabric samples or mannequins wearing clothing items are positioned around an arcing electrode at a specified distance. Calorimeters are placed besides and behind the test specimens to record both the arcing energy and the energy transferred through the clothing item. At least twenty different tests are undertaken at varying energy levels to determine the statistical performance of the item under test.

Test Results

The results of the open arc test are published in the form of an arc rating value, typically given in calories per square centimeter (cal/cm2). As of the 2019 edition of the standard the following arc rating values may be assigned:

  • The Incident Energy Limit Value (ELIM)
  • The lower of the Arc Thermal Performance Value (ATPV) or the Energy Breakopen Threshold (EBT50)

The ELIM rating is the maximum thermal energy an item can withstand without breaking open and whilst entirely preventing the chance of onset of second-degree burns by heat transfer.

The ATPV is the maximum thermal energy an item can withstand with the wearer having a 50% chance of experiencing the onset of second-degree burns.

The EBT50 is the thermal energy value at which there is a 50% chance of the item breaking open (i.e. a hole forming) that would lead to burn injury.

Whether the ATPV or EBT50 value is reported simply depends on the way the items fails when exposed to heat. The ELIM value was introduced in 2019 as a more conservative rating. The ELIM will be the lowest rating of the three given the more stringent criteria applied.

The international standard IEEE 1584 provides a methodology for determining by calculation the prospective arc flash Incident Energy at a particular piece of electrical equipment. This can then be used to determine the requirement for PPE that has been rated in accordance with IEC 61482-1-1.

IEC 61482-1-2: Box Test Method

The latest UK version of this standard is BS EN 61482-1-2:2014.

This is a test method for determining the Arc Protection Class of material and clothing by using a constrained and directed arc. This is more commonly known as the box test method. It is an easier test to undertake but has a limited range of outcomes.

Test Process

In the box test the fabric sample or clothing garment is placed in front of an open box which contains electrodes. This simulates a constrained and directed arc more akin to that occuring in an enclosed panel or switchgear compartment.

The test specimen is placed 300mm away from the front of the box. Two different arc current levels are used: 4kA and 7kA, with an exposure time of 0.5 seconds. The heat transferred through the sample is measured using calorimeters placed behind the test sample. Typically four samples are tested.

Test Results

After testing each sample is inspected to determine whether it meets all the acceptance criteria. Depending on the maximum current it passed at, it is assigned an Arc Protection Class (APC) of 1 or 2:

  • If it passes at 7kA then it is assigned APC 2.
  • If it passes at 4kA but fails to pass at 7kA then it is assigned APC 1.
  • If it fails to pass at 4kA then it is not classed.

The German standard DGUV-I 203-077 provides a way to determine by calculation the required APC for a particular piece of electrical equipment. This can then be used to select PPE that has been rated in accordance with 61482-1-2.

Protection of Face, Hands and Feet

BS EN IEC 62819 Live working - Eye, face and head protectors against the effects of electric arc - Performance requirements and test methods was published in 2023. It covers the testing and subsequent rating of items such as hoods, goggles, balaclavas, faceshields and helmets. As a relatively new standard there are limited products available which have been tested to it, but it is expected that this will change over the next few years as it sees wider adoption.

The IEC has in development IEC 63232-2 which is intended for hand protection. It is due to be published in late 2025.

Arc-rating of safety footwear is not something that is currently covered by the IEC.