The Importance of Visibility in Electrical Work

By: Mike Enright

One of the most common tropes in an action movie is the element of defusing a time bomb. Often, the protagonist will find him or herself in a room with an explosive device, tasked with cutting the right wires in order to save themselves and often others from destruction. Should the hero cut the green or the blue wire? What happens if they cut the wrong wire?

While the theme has been overused and is extremely unrealistic (in terms of bomb disposal), what if the movie’s hero couldn’t tell the difference between blue, green, white, and yellow when choosing which wire to cut?

There are real life situations in which color recognition is a life and death matter, and telling the difference between yellow and white or green and blue is imperative. Energized electrical work requires a keen eye, but workers have had to complete this work without being able to see the entire spectrum of colors for too long. Today, we would like to look at the basics of color perception and some of the reasons legacy green face shields add undue risk to electrical work.

A Brief Look at the Color Spectrum

The human eye sees color over wavelengths ranging roughly from 400 nanometers (violet) to 700 nanometers (red). This range of color represents what is called the “visible light spectrum,” and these colors correspond to narrow wavelength bands—red, orange, yellow, green, blue, indigo, and violet; wavelengths of visible light match the following frequencies:

• Violet: 380-450 nm (688-789 THz frequency)
• Blue: 450-495 nm
• Green: 495-570 nm
• Yellow: 570-590 nm
• Orange: 590-620 nm
• Red: 620-750 nm (400-484 THz frequency)

Legacy Green Face Shields: A Muddled Mess

Arc flash events generate an immense amount of infrared light, and traditionally, face shields contained a green tint that could absorb infrared light. This green dye was designed for the protection of workers in the unfortunate event of an arc flash; the higher the level of protection, the darker the face shield. The darker the face shield was, the more intense the green color was, meaning that a face shield designed for PPE CAT 4 exposures would absorb the most light but would also filter out a wider range of colors from entering the eye.

This meant that the higher the level of protection used, the fewer colors a worker could see. Yellow would appear white, green would appear blue, and workers would have to make judgements on a limited range of visibility.

For many years, this was just “part of the job,” as green was the only option available. However, in recent years, technology has advanced, and modern face shields exist that can absorb the infrared light from an arc flash without relying on green dye to do so. Offering the same level of protection without compromising color recognition, these face shields provide the best of both worlds.

The Alternative: OptiShield™ Grey Face Shields

When employees complete energized electrical work, they need unmatched visibility, color recognition, and safety; legacy green face shields only offer one or two of these.

However, Enespro PPE has a new line of face shields that are arc-rated without sacrificing color recognition or visibility. Enespro OptiShield^TM grey nanoparticle shields to offer a highly transparent alternative to legacy green.

Enespro OptiShield^TM grey nanoparticle shields have improved visibility and color versus legacy green tinted shields. They also include an abrasion resistant coating on the front surface and a permanent anti-fog coating on the interior.

The OptiShield^TM Vented Lift-Front Shield allows for easy access to fresh air when out of the hazard boundary. The multiple vents improve air-flow and reduce fogging while in the hazard boundary. The auditory vents improve hearing and communication.

Learn more about Enespro OptiShield^TM grey nanoparticle shields, available in 12 CAL and 40 CAL models by clicking here.