Arc Flash Testing Glossary

Common phrases and terms used in arc flash testing with references for our clients and perspective arc flash testing clients.

Arc Flash (or arc blast)

A type of electrical explosion that results from a low impedance connection to ground or another voltage phase in an electrical system. [It ejects heat and a pressure wave and typically includes plasma and molten metal or shrapnel depending on the source and electrode configuration relative to the worker location. The pressure wave increases in intensity with the fault current.] 6 There are 4 Types of Arcs: open air, ejected, arc-in-a-box, and tracking arc.

Arc Rating

A value attributed to describe the performance of a material when exposed to an electric arc, designated as ATPV or EBT.


An American National Standard for Conformity Assessment of Safety and Personal Protective Equipment. This standard, which was released this year, outlines three different levels of conformity assessment. See our article for more information.

ANSI 107

High Visibility Clothing-test methods and requirements. Requires "FR" to meet proper "FR" Clothing Standards.


ASTM International, formerly known as the American Society for Testing and Materials (ASTM), is a globally recognized leader in the development and delivery of international voluntary consensus standards. ASTM was the first organization in the world to develop arc flash standards for garments and most other PPE.

ASTM D6413

A Standard Test Method for Flame Resistance of Textiles (Vertical Test). Does not have requirements; only a test method which is referenced by many specifications.

ASTM F1506

A Specification for Materials used to make clothing for workers who may be exposed to the thermal hazards of a momentary electric arc.

ASTM F1891

A Specification for rainwear used for workers who may be exposed to the thermal hazards of a momentary electric arc.

ASTM F1958

A Standard test method for Determining the Ignitability of Non-flame-Resistant Materials for Clothing by Electric Arc Exposure Method Using Mannequins

ASTM F1959

A Standard Test Method for Determining the Arc Rating of Materials for Clothing. Used for compliance with ASTM F1506, ASTM F1891, and NFPA 70E.

ASTM F2733

A Specification for rainwear worn by workers with exposure to flame hazards.

ATPV (Arc Thermal Performance Value)

The incident energy on a material that results in a 50% probability that sufficient heat transfer through the specimen is predicted to cause the onset of second-degree burn injury based on the Stoll Curve, cal/cm2.


A common unit of energy per unit area to describe protective values of arc rating used in arc flash. Can also be Joules/cm2 or Joules/m2. As little as 1.2 cal/cm2 can cause second degree burn in human tissue from an infrared heat lamp. But 2 cal/cm2 is a common amount believed to be the burn threshold in arc flash based on arc flash research by Duke Energy.


An Amount of energy required to raise the temperature of one gram of water one Celsius degree.

CGSB 155.20

A Workwear for Protection against Hydrocarbon Flash Fire. This is the Canadian version of NFPA 2112.


In physics, the transfer of heat by the movement of heated parts of a liquid or gas7.


High Visibility Clothing-test methods and requirements for Canada. Allows "bright clothing" in FR applications.

CSA Z462 (Canadian ANSI 107)

The Canadian version of ANSI 107 for high visibility products.

EBT (Energy Breakopen Threshold)

The incident energy on a material that results in a 50% probability of breakopen. Breakopen is defined as any open area at least 1.6 cm2 (0.5 in.2).

Flash Fire

A rapid moving flame front which can be a combustion explosion.

Flame Resistance

The property of a material whereby combustion is prevented, terminated, or inhibited following the application of a flaming or non-flaming source of ignition, with or without subsequent removal of the ignition source 8.

Flame Retardant

A chemical used to treat materials to make them flame resistant. Flame retardants are used to prevent the spread of fire.

IEC 61482-1-1 - Live working

Protective clothing against the thermal hazards of an electric arc - Part 1-1: Test methods - Method 1: Determination of the arc rating (ATPV or EBT50) of flame resistant materials for clothing5.An open air arc is used in this test method. Method A is used for textiles, and Method B is used for garments and accident investigations.

IEC 61482-2

Protective Clothing against the thermal hazards of an electric arc- Part 2 Requirements. This is the IEC version of ASTM F1506.

IEC 61482-1-2 - Live working

Protective clothing against the thermal hazards of an electric arc - Part 1-2: Test methods - Method 2: Determination of arc protection class of material and clothing by using a constrained and directed arc (box test.)


See "The Institute of Electrical and Electronics Engineers"

ISO 9001 - Quality Management Systems Requirements

This standard is used by manufacturers to achieve consistency and continually improve.

ISO 11612 - Protective Clothing

Clothing to protect against heat and flame. This standard superseded the former EN 531. EN ISO 11612 is for the whole garment, as opposed to just the fabric.

ISO 17025

General requirements for the competence of testing and calibration laboratories. This standard is used by laboratories to achieve accreditation. Laboratories must demonstrate technical competence, continuous improvement, and a quality management system through auditing in order to become accredited.

ISO 20471

High Visibility Clothing-test methods and requirements. Previously EN 471. Similar to ANSI 107 and CSA Z96.

National Electric Code (NFPA 70, ANSI C-1)

NFPA 70 has been adopted in all 50 states to be used as the benchmark for safe electrical design, installation, and inspection to protect people and property from electrical hazards1.

National Electric Safety Code (NESC, ANSI C-2)

Sets rules for the practical safeguarding of persons during the installation, operation, or maintenance of electric supply and communication lines and associated equipment. 2 The NESC focuses on electrical and communication equipment like the cable company and the electric utility or those types of installations in large industrial plants.


A Standard for Electrical Safety in the Workplace "How you work on it."

NFPA 2112

A Standard on Flame Resistant Garments for the Protection of Industrial Personnel against Flash Fire Hazards. This standard requires third party certification.

NFPA 2113

Standard on Selection, Care, Use, and Maintenance of Flame-Resistant Garments for Protection of Industrial Personnel Against Short-Duration Thermal Exposures.

Product Specification

A company specification for a bid usually based around Standard Specifications, testing, accreditation requirements, and manufacturer quality control requirements. (i.e. Long sleeved shirts meeting ASTM F1506 manufactured to ANSI 125 Level two, including ISO 17025 accredited lab results and manufactured in an ISO 9001 accredited plant. The minimum arc rating shall be 4 cal/cm2 and the maximum weight shall be 5 oz/yd2).

Radiant Energy

Energy traveling as electromagnetic waves7.

Standard Specification

An explicit set of requirements to be satisfied by a material, product, system, or service. A specification identifies the test methods for determining whether each of the requirements is satisfied9.

Standard Test Method

A definitive procedure that produces a test result. For example, identification, measurement, and evaluation of one or more qualities, characteristics, or properties9.

The Institute of Electrical and Electronics Engineers (IEEE)

A professional organization dedicated to advancing technological innovation and excellence for the benefit of humanity3.

US Occupational Safety & Health Administration (OSHA)

Part of the Department of Labor that was created by Congress to assure safe and healthful working conditions by providing training, outreach, education, and assistance, and by enforcing standards4.


Below are the places we got our information form.






6 Adapted from:


8 NFPA 2113

9 ASTM Blue Book