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NFPA 70E

This article is provided courtesy of Snell Infrared, a thermographic training company.

If you have not yet heard about NFPA 70E, you soon will. For electrical thermographers the impact will be profound. Some will view it as a hassle, others as a welcomed assurance to personal safety. Regardless of your viewpoint, NFPA 70E will soon be the basis of new OSHA regulations for infrared thermographers throughout the United States.

The National Fire Protection Association (NFPA) is perhaps best known for it's research and standards, especially the National Electrical Code (NFPA 70). Several other documents make up the 70 series, including NFPA 70E, Standard for Electrical Safety Requirements for Employee Workplaces, 1995. This standard is available at many bookstores or call John Snell (800-636-9820) for details on how to order it.

What is the impact of NFPA 70E? For thermographers conducting electrical inspections the greatest changes in work habits will relate to protection from an electrical arc flash. Also, thermographers who are not qualified electricians must now be accompanied by qualified personnel. If you conduct electrical inspections, get a copy of NFPA 70E, read it, understand it, and learn to work within them. You may also take some comfort in the possibility that following 70E could save your life!

Hazardous flash can occur in any electrical device, regardless of voltage, in which energy is high enough to sustain an arc. This includes many 440V motor control centers, panel boards, and switch boards. An arc of this type, while typically less than a second in duration, can reach temperatures in excess of 14,000deg.F--high enough to produce extensive first degree burns, permanent blindness, or death.

NFPA 70E specifies boundaries within which flash protection is required in an effort to reduce the extent of injuries. Protective equipment is also specified including flash resistant clothing and face shielding. Boundary distances vary depending on both the qualifications of the person being exposed and the voltage involved. Unqualified personnel must be accompanied by qualified personnel. All personnel within the defined boundaries must wear specified protective equipment.

The following boundary distances for flash protection have been established in NFPA 70E: If you are working within the following approach distances, flash protection is required:

Voltage Flash Protection Boundary

up to 750V	3 feet
750V to 2kV	4 feet
2kV to 15kV	16 feet
15kV to 36kV	19 feet
over 36kV	Must be Calculated

Flash protection equipment includes flash resistant clothing and face and neck shield. Flash resistant personal protection equipment will not protect you from shock, but it will give substantial protection from the effects of flash, especially burns and eye damage.

Flash protective clothing is specified by ASTM F1506 while eye protection must comply with ANSI Z87.1. Clothing coverage must be 100%, i.e. coveralls or shirt and trousers. Eye protection can include either a face shield (with neck protection) or "bee keeper's hood." Eye protection will provide significant filtering of the damaging ultraviolet (UV) radiation associated with a flash. This equipment is available from various vendors, including the following:

Clothing made from Nomex®: Workrite Uniforms (805-483-0175) Eye Protection: Oberon Company (800-322-3348)

If you are conducting electrical inspections, it is time to learn how to comply with NFPA 70E. Start by getting a copy and becoming familiar with it. Meet with your management and safety committee. Develop training and work procedures that enable you to meet these important new standards and improve safe work conditions for thermographers at the same time. And remember, this standard exists not to create more problems in your work life, but to prevent your work from costing you your life!

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