Fit and function

With objects swinging and dust flying, a construction job site is not easy on the eye. To prevent injuries, start with the proper glasses, and make sure they fit

By Fred Ravetto, vice president of sales, Elvex Corp. -- Industrial Distribution, 10/1/2006

Every day an estimated 1,000 eye injuries occur in American workplaces, with more than 20 percent of those injuries occurring in the construction industry. Eye injuries make no distinction amongst workers, adversely impacting skilled and unskilled laborers alike. The financial cost of these injuries is enormous, but no dollar figure can adequately reflect the personal toll these accidents take on the injured workers.

Not wearing eye protection at all, and wearing the wrong kind of eye protection, are the primary causes of eye injuries in the workplace. The Bureau of Labor Statistics reports that nearly three out of every five workers injured were not wearing any eye protection.

Flying particles are the primary cause of eye injuries, with almost 70 percent of accidents resulting from flying or falling objects or sparks striking the eye. Injured workers estimated that nearly three-fifths of the objects were smaller than a pin head. Contact with chemicals caused one-fifth of the injuries. Other accidents were caused by objects swinging from a fixed or attached position, such as tree limbs, ropes, chains, or tools, which were pulled into the eye while the worker was using them.

Workers should always wear eye protection that meets ANSI standard Z87.1-2003 (Z87+), and when choosing safety glasses, make sure they are properly fitted. Remember that wearing poorly fitted or the wrong kind of eye protection is a major cause of eye injuries. A BLS survey showed that 94 percent of the injuries to workers wearing eye protection resulted from objects or chemicals going around or under the protector. Every person is different, and so is the shape of each individual's face, so wearing a proper-fitting pair of safety glasses is critical to preventing eye injuries from occurring.

What is a proper fit? A proper fit provides wraparound protection on the sides and a close fit at the brow and cheeks to protect from flying objects, while allowing for air circulation between the eye and the lens. Another important note on prevention is that there are jobs where exposure to particulates or chemicals requires a higher level of protection for the eyes. The use of goggles is a step up in safety and protection for these harsh environments. The best possible protection is afforded when goggles are worn in combination with face shields.

Safety glasses with polycarbonate lenses are by far the leading choice for eye protection against flying debris, and they also offer protection from ultraviolet light exposure. A properly designed and tested polycarbonate safety glass complies with ANSI Z87 requirements for impact velocity, mass impact, lens thickness, lens distortion, and light transmission.

Polycarbonate safety glasses provide an excellent combination of impact resistance and optics. When properly designed, they are lightweight, comfortable, and stylish, at a cost that is much lower than designs from decades ago. Polycarbonate is the lens of choice for safety glasses. Its impact resistance is the reason why polycarbonate is used in “bullet proof” windows, and in other applications requiring flexibility and strength. One might expect a material that is as strong as polycarbonate to also be very strong in other respects, such as scratch resistance. Polycarbonate gains its strength from being flexible instead of rigid. Because of this, polycarbonate lenses are prone to scratching and require a hard coating, especially for dusty and abrasive construction site environments.

Wraparound safety: The OSHA regulation for eye and face protection 29 CFR # 1910.133 states that, “Employer[s] shall ensure that each affected employee use eye protection that provides side protection when there is a hazard from flying objects.” Properly-designed wraparound-style safety glasses will meet this standard.

Perhaps one of the leading innovations in the last few years has been the introduction of wraparound safety glasses that are stylish. Although style is not the first thing that comes to mind in the construction industry, it is style that motivates many workers to wear their glasses and to keep them on throughout the work day. Many companies have decided to embrace this trend in the interest of safety and lowering workplace injuries. Companies that choose a selection of stylish glasses find that compliance problems drop dramatically. Wraparound safety glasses are evidence of this style change, with the close-fitting nature of the wraparound eliminating old-fashioned side shields.

Bifocal safety glasses: Another demographic trend is the aging of our nation's workforce. As workers pass the age of 40, many will require reading glasses. Several years ago, Elvex Corp. responded to this market need by introducing the first line of RX reading safety glasses made of polycarbonate lenses. Today, workers have the ability to read prints and manuals, and do close-up work in a safe and cost-effective way.

More and more companies are making safety bifocals available to their workforce at a fraction of the cost of prescription safety glasses. One innovative design combines bifocal lenses in a stylish, lightweight and comfortable pair of safety glasses. This model has a contemporary wrap frame and, most importantly, is fully ANSI Z87+ compliant with supporting test reports. Other features include: transparent gray polycarbonate frame, soft rubber nose bridge, and rubber-tipped temples. Eye strength varies from worker to worker, so models come in a choice of bifocal powers (diopters): 1.0, 1.5, 2.0, 2.5 and 3.0. For outdoor construction workers these glasses are available in gray (sunglass) lenses. Bifocal safety glasses have become a big market, and users are asking for more choices in frame styles, comfortable protection, high quality, and of course, full ANSI standard compliance.

Safety sunglasses: Good quality safety sunglass models have NCB (Natural Color Balance) gray lenses to provide protection against bright visible light and ultraviolet light, as well as Blue Light and Infrared Protection. Due to changes in the atmosphere, ultraviolet levels are much higher than in the past, meaning ultraviolet protection for eyes is even more important. Construction workers can be at risk for exposure, especially when employed at high-altitude job sites. Be wary when selecting sunglasses, as many brands offer more style than protection, and many are not ANSI Z87-rated safety glasses.

Although UV and IR light is invisible to the human eye, it nonetheless can have dangerous effects. UV light can damage the eyes in several ways. Excessive exposure to the lowest wavelengths of UV light, also called UV-C (180-290 nm), can cause damage to the cornea as well as the lens. These wavelengths are not common in nature, since they are absorbed by the atmosphere, but are present in some industrial environments, such as electric arc welding.

Mid UV light is present in sunlight, and these mid wavelengths (UV-B, 290-320 nm) can cause damage to the eye's lens. The high UV wavelengths (UV-A, 320-380 nm) are present in all outdoor environments. Excessive exposure can cause fatigue or snow blindness. Blue light (380-480 nm) can cause damage to the retina (the back of the eye). Blue light is present in regular sunlight, as well as office environments (computer screens generate blue light).

Polarized glasses: While normal sunglasses decrease the intensity of all light by a uniform percentage, polarized sunglasses selectively eliminate the light coming from a reflective surface. When the sun shines at the sea or any other reflective or partially reflective surface, the reflected light becomes polarized. Typical examples in construction occur when working near water, glass or metal buildings, or around construction vehicles.

Whenever reflections are incoming off natural or man-made surfaces, polarized glasses can be a wise choice for protective eyewear. Polarized lenses allow only light in one plane to pass through the lens. Therefore, much of the glare can be eliminated. Polarized glasses will not help if the wearer is looking directly at the sun or light source. However, they will benefit whenever the reflected light is at an angle between 30 degrees and 60 degrees.

Over Specs safety glasses: These are designed specifically to fit over prescription glasses. This style is “frame free” and has a flatter lens curvature to minimize reflection that may occur when dual spectacles are worn. When selecting this style of glass, be sure the temples offer adjustment for both length and angle so they fit over most prescription glasses.

Goggles: Goggles are protective eyewear that fully cover and protect the eye area to provide a higher level of protection from particulates or chemicals that may strike the eyes. Goggles are often worn when using high-speed power tools such as table saws, drills, and chainsaws to prevent flying particles from damaging the eyes. They are recommended whenever working in an area where chemical splashing can occur.

The ANSI standard covering goggles is ANSI Z87+, so be sure that goggles are rated for this standard and have supporting test reports. Since goggles are form-fitted on the face, be sure the goggles are of a comfortable, soft material. Also, they should have indirect ventilation for air circulation and an anti-fog lens coating. Fogging can be a real challenge with goggles, so a popular goggle to choose has two layers of lenses that prevent the interior from becoming “foggy.” Dual-lens goggles have an inner lens of acetate on which anti-fog treatment adheres exceptionally well. Overall, a well-designed, full-coverage goggle combines impact resistance with coverage that prevents debris or chemical splashes from reaching the eyes.

Electric arc protection: Electrical workers in the construction industry risk exposure to a sudden release of energy that occurs during an electrical arc. This is a very dangerous condition that can result in serious burns and death. There have long been requirements established for safety clothing to be used by these workers, but starting January 1, 2003, it was required that electrical workers use face protection meeting similar requirements.

The National Fire Protection Assn.'s standard NFPA 70E-2000 establishes Hazard or Risk categories. Certain ARC-Shields are suitable for use in hazard/risk categories 1 and 2. The minimum Arc Thermal Performance Value (ATPV) has been established to be 5 cal/cm² and 8 cal/cm² for these two risk categories. (Cal/cm² stands for calories per square centimeter). This type of shield has special fillers to protect from flashes, and it should be noted that for full protection the complete system must include a safety cap.

Welding shades: There are a number of options for welding applications, all of which require shaded lenses to match with the intensity of the electric arc current in use. Attention must be paid to the welding equipment manufacturer's recommendation for weld shade and level of protection required. Welding without the proper precautions can be hazardous, so special care must be given to the type of coverage selected, ranging from safety glasses to face shields to welding hoods and full suits.

Be sure not only to choose the right equipment for a specific application, but also pay close attention to fit as well as function. The right equipment poorly fitted is a significant cause of eye injuries.