The National Fire Protection Association (NFPA) is a global nonprofit organization, established in 1896, devoted to eliminating death, injury, property and economic loss due to fire, electrical and related hazards.

The International Organization for Standardization, is an independent, non-governmental organization, the members of which are the standards organizations of the 162[1] member countries. It is the world’s largest developer of voluntary international standards and facilitates world trade by providing common standards between nations. Over twenty thousand standards have been set covering everything from manufactured products and technology to food safety, agriculture and healthcare.[3]

Use of the standards aids in the creation of products and services that are safe, reliable and of good quality. The standards help businesses increase productivity while minimizing errors and waste. By enabling products from different markets to be directly compared, they facilitate companies in entering new markets and assist in the development of global trade on a fair basis. The standards also serve to safeguard consumers and the end-users of products and services, ensuring that certified products conform to the minimum standards set internationally.

Per NFPA 70E, the Standard for Electrical Safety in the Workplace, a hazard risk category (HRC) represents the potential level of risk or danger involved in completing a job responsibility. These categories are dependent on the the incident energy (measured in cal/cm²), and help to determine the appropriate flame resistant clothing (FRC) needed to safely perform the task at hand.

Hazard risk categories range from HRC 0 (least potential risk) to HRC 4 (highest potential risk). The higher the HRC, the higher the cal/cm² rating must be to ensure protection from arc flash hazards. For instance, an HRC Level 1 garment must have a minimum of 4 cal/cm², whereas an HRC 4 garment must meet a minimum of 40 cal/cm².

Garments compliant to HRC (Hazard Risk Category) 2, as defined by NFPA 70E, 2012 edition, have an arc rating that is greater than or equal to 8 cal/cm², but is less than 25 cal/cm².

HRC 2 may also be called Level 2. In some cases, incorrectly, users may refer to HRC 2 as Class 2. Class 2 applies to ANSI standards, and other standards, but not to NFPA 70E. HRC and Level are correct identifiers. To ensure correct communication of a need, use the arc rating.

Garments compliant to HRC 2 are often referred to as daily wear. Daily wear includes, but is not limited to: knit or button front FR shirts, work pants or FR jeans and coveralls. NOTE: Not all daily wear is compliant to hazard risk category 2. Be sure to check the arc rating to confirm that the garment will provide the necessary protection.

Garments compliant to HRC (Hazard Risk Category) 3, as defined by NFPA 70E, 2012 edition, have an arc rating that is greater than or equal to 25 cal/cm², but are less than 40 cal/cm².

Garments compliant to HRC (Hazard Risk Category) 4, as defined by NFPA 70E, 2012 edition, have an arc rating that is greater than or equal to 40 cal/cm².