Arc Flash Safety Glasses Explained

Arc Flash Safety Glasses
Arc Flash is a short circuit that flashes from one exposed live conductor to another, or to ground. The resulting ionized air creates electrically conductive superheated plasma can reach temperatures of 5000 degrees F or greater in less than a second, creating an explosion equivalent to several sticks of dynamite. This can easily damage eyesight if Arc flash safety glasses are not used.

Accompanying this traumatic event is a brilliant flash and intense heat, which requires those working in arc flash environments to include protective eyewear as a part of the personal protective equipment ensemble (PPE).

Arc flash safety glasses are normally made of non-conductive frames that are shatterproof, anti-static, UV protected and anti-fogging — and usually offer some form of protective side shielding (protecting the face and side of the eyes as much as possible).

Arc Flash Safety Glasses
The requirement for Arc Flash Safety Glasses are needed even at hazard category 0, long before the need for an arc-rated face shield is necessary at category 2 (arc rating of 8 cal/cm2).

Before determining the need for arc flash safety glasses (or more importantly, if greater protection is needed), an arc flash study of incident energy needs to be known so workers may know where they need the proper PPE to work on energized equipment.

These calculations need to be performed by a qualified person such as an electrical engineer. All parts of the body that may be exposed to the arc flash need to be covered by the appropriate type and quality of PPE.

Proper PPE can include flame resistant clothing, helmet or headgear, face shield, safety glasses, gloves, shoes, etc. depending upon the level of potential arc energy.

The standards and regulations governing arc flash include:

• OSHA Standards 29-CFR, Part 1910. Occupational Safety and Health Standards. 1910 sub part S (electrical) Standard number 1910.333 specifically addresses Standards for Work Practices and references NFPA 70E.
• The National Fire Protection Association (NFPA) Standard 70 - "The National Electrical Code" (NEC) contains requirements for warning labels.
• NFPA 70E provides guidance on implementing appropriate work practices that are required to safeguard workers from injury while working on or near exposed electrical conductors or circuit parts that could become energized.
• The Institute of Electronics and Electrical Engineers (IEEE) 1584 - Guide to Performing Arc-Flash Hazard Calculations.

In Canada, CSA Z462 is the standard that replaces NFPA 70E. All glasses should meet the minimum ANSI Z87.1 (U.S.) and CSA Z94.3 (Canadian) standards.