Beyond Light vs. Dark: Why Color Rendering Is a Critical Safety Factor in Hazloc Lighting
Color rendering is a critical safety factor in hazardous location lighting, impacting visibility, color accuracy, and risk mitigation beyond basic brightness levels.
When most people hear the phrase “adequate lighting” in an industrial setting, they immediately think about brightness and the level of visibility. Certainly, that’s important for employee safety. Studies show that adequate illumination can reduce the risk of slips, trips and falls by up to 60 percent.
But brightness isn’t the only factor to consider. Industrial sites must also ensure their lighting delivers color accuracy: vivid and true-to-life color rendering that allows workers to easily distinguish between colors. While this might seem more like a convenience than a necessity, the ability to discern colors is a fundamental safety factor in harsh, hazardous settings, and therefore the right lighting plays an essential role in risk mitigation.
The Critical Role of CRI
How accurately a given light source portrays color is measured on the Color Rendering Index (CRI). This scale, ranging from 0 to 100, uses natural light as its benchmark for the most accurate color rendering possible: 100 CRI. A light source with a higher CRI rating indicates that objects illuminated by it appear more vivid and true, while lower CRI ratings (typically below 80) mean that light source may make colors appear distorted.
This effect is very common in daily life. Think about how the orange glow of common high-pressure sodium (HPS) streetlights make your car look a completely different color at night or how your favorite blue shirt looks black or even purple in certain lighting.
Correlated color temperature (CCT), measured in Kelvin (K), also plays a role, and this measure is based on the natural daylight color spectrum. You’ve probably also encountered CCT in daily life—most household light bulbs are sold in a range of warm, soft white or bright white light. Some people wear blue light blocking glasses to filter out that part of the spectrum to avoid eye strain and sleep disruption.
In industrial and hazardous location lighting, there’s a stark contrast in color rendering between the types of lighting commonly used. Traditional light sources, such as HPS, have a CRI as low as 60 and can cause severe distortion of colors. Fluorescent lamps are slightly better, ranging from 60 to 80 CRI. By contrast, modern industrial LED lighting delivers a much higher CRI—as high as 97, or virtually as close to natural daylight as possible for artificial lighting.
Color Rendering Is a Safety Concern
This variability in lighting CRI not only impacts general visibility, but also has significant implications for risk mitigation.
Safety signs and warning placards with different color indicators are everywhere in an industrial site and poor CRI lighting affects staff’s ability to make smart, safe decisions. Low CRI can make it difficult to distinguish the color of electrical wiring, machine parts, pressure gauges and workspaces. Under HPS lighting, maintenance workers could easily mistake an orange wire for the emergency red one and risk electrocution by cutting the wrong wire. Under HPS lighting, it can be nearly impossible to discern a hydraulic fluid spill from an oil spill. It can also be hard to identify which valves to adjust or when to adjust them if gauges can’t be seen clearly.
Because of the poor CRI of most conventional lighting fixtures, workers often have to use supplemental lighting to improve visibility. This not only requires additional equipment but also impacts their efficiency and personal safety. If they’re having to hold flashlights, constantly adjust headlamps or work around portable lighting, it’s distracting, cumbersome and creates tripping hazards.
Poor CRI lighting also impacts morale and alertness, which compounds jobsite risk. A dark, dingy atmosphere makes work feel like drudgery, hinders motivation, and often hides dirt and debris, contributing to a dirty, unpleasant environment. This can result in drowsiness, complacency and lack of engagement, all of which creates a safety issue in an industrial setting where risk is around every corner and workers need to be on their A-game to remain vigilant.
To make matters worse, these problems become more profound over time as fixtures age. Light loss depreciates lighting intensity, and as lights fail, color shift accelerates. Considering that conventional lighting like HPS fixtures are lucky to last 18 months in a heavy industrial or hazardous setting, the unfortunate reality is that workers operate the majority of time in a low-visibility, low-CRI environment.
Mitigating Risk With Better CRI
To protect workers against accidents and injury—and to mitigate liability—organizations must consider the overall performance of their lighting fixtures. Here are four ways to maximize safety through better CRI:
- Prioritize color accuracy. Organizations often overlook the role of color accuracy when selecting lighting, instead focusing exclusively on cost, efficiency and brightness. Fortunately, lighting sources like LED fixtures can deliver on all four requirements with high CRI, lower total cost of ownership, superior energy efficiency and brightness that mimics natural daylight.
- Consider the application. The design of the fixture itself can impact color perception. For hazardous locations, even LED fixtures must be sealed to prevent explosions. This, along with the design adjustments required to dissipate heat and cleanliness of the lenses can impact the CCT and CRI. Work with a supplier who can design a lighting scheme that takes these factors into consideration to get the best result.
- Be proactive about safety. Too often, organizations wait until lighting has become a problem to make a change. In one facility, an individual was severely cut on the job, but because of the combination of his skin color and the color of his blood under poor CRI lighting, first responders couldn’t locate the cut on his body right away. The better strategy is to implement proactive measures that include assessing lighting conditions and their impact on safety. If color clarity is a recognized problem, change out the lights before it creates an incident.
- Standardize lighting across the facility. Industrial sites often use a variety of lighting sources, creating challenges for workers transitioning between areas. Think about driving through a tunnel even in the daytime, going from natural to artificial light and back to natural light again. It’s challenging on the eyes. The more frequently workers’ eyes have to make the transition, the harder it becomes, reducing visibility and causing eye strain that can impact their vision long term. By contrast, standardizing on ruggedized LED fixtures across your facility provides consistent, reliable, high-CRI illumination without harsh transitions required. Plus, it presents a clean, more professional and safe appearance.
But just as important as the visibility is the drastic improvement in color rendering. The ability to accurately discern colors, especially in hazardous locations, improves communication, productivity, and job performance while enhancing risk mitigation to protect workers from harm.