Incident Prevention Magazine

Employees who interact with electrical equipment and electrical installations may be exposed to electrical shock and arc flash hazards. A previous two-part article titled “Arc Flash Considerations for Utility and Construction Activities” (see https://incident-prevention.com/ip-articles/arc-flash-considerations-for-utility-and-construction-activities and https://incident-prevention.com/ip-articles/arc-flash-considerations-for-utility-and-construction-activities-part-ii) discussed the electrical hazard identification and risk assessment. If the employer has taken steps to reduce the risk of injury or death from electrical hazards but is unable to eliminate the hazard, then OSHA requires the provision of adequate personal protective equipment (PPE). For electrical hazards, both dielectric (insulating) and arc-rated (thermal) PPE is required. This article discusses some of the ASTM International and National Fire Protection Association (NFPA) standards for arc flash-related PPE. Many ASTM standards have equivalent International Electrotechnical Commission (IEC) standards. These standards reference the International Organization for Standardization (ISO), American National Standards Institute (ANSI), American Association of Textile Chemists and Colorists, and so forth. While no one standard may claim superiority over another, it is a best practice to ensure that products meet the local performance specifications. Nearly all North American labs that work with arc-rated (AR) PPE are geared toward performing both local and international testing.

This article concludes a two-part discussion of protection strategies against arc flash and shock hazards. Here you will read about two topics: (1) arc flash and shock hazard labeling for industrial, commercial and generation facility electrical exposures, and (2) methods used to determine the level of PPE required.

The previous article (see https://incident-prevention.com/ip-articles/arc-flash-considerations-for-utility-and-construction-activities) mentioned that utilities follow OSHA 29 CFR 1910.269 and construction companies follow either 1926 Subpart K or 1926 Subpart V, depending on the job site. It discussed arc flash and shock hazards as a basis for selecting appropriate PPE to protect against each hazard. It also reviewed the consideration and provision of daily workwear and flash suits as well as voltage-rated gloves for low- and high-voltage work. Part II will explain the methods used to determine the level of PPE required through an arc flash incident energy analysis or engineering study. Equipment-specific labeling is the most widely used method to communicate the level of protection to workers. Arc flash and shock labeling will be presented using examples and serve as a backdrop to the introduction of key terminology used in electrical safety.

Electrical safety-related work practices are governed by different OSHA regulations for utilities and construction companies. Utilities follow 29 CFR 1910.269 and construction companies follow either 1926 Subpart K or 1926 Subpart V, depending on the job site. It wasn’t until the 1910.269 revisions in 2014 that OSHA used direct wording mandating arc-rated clothing. And while it may seem that five years is enough time to install an organization-wide PPE program, it is not uncommon to find such programs lacking. Recently, a utility’s operational team confirmed that they normally operate a piece of equipment while wearing street clothing. While this practice may not be a problem in certain limited cases, in this instance the garment labels prohibited any energized work based on the high arc flash energy. The problem was, these workers failed to realize that switching off is considered energized work. Serving as independent safety consultants to various construction companies and utilities has offered us a great deal of insight into similar hazardous operating conditions, but at the same time has allowed for testing and implementing what works in these environments. This article, the first in a two-part series, introduces the concepts of arc flash and shock hazards, followed by a discussion about personal protective equipment (PPE) that guards against those hazards. The second article in this series will provide guidance on how to effectively communicate the adequate level of protection to workers.