Our employees encounter countless hazards at the workplace, many of which jeopardize their eyes and vision. A study conducted by the Bureau of Labor Statistics found that 100 of the 2,000 eye injuries that occur each day cause employees to miss one or more days of work. Also 60 percent of eye-related accidents resulted from workers not wearing any protection, and 40 percent resulted from wearing the wrong type. The study also found that around 70 percent of all eye accidents resulted from flying objects, particles and sparks; 60 percent of these objects were smaller than a pin head and were travelling faster than an object thrown by hand. Amazingly, almost 40 percent of those injured received no eye protection training.
As a company owner, it is your responsibility to choose the best and most appropriate type of safety eye protection to help reduce the possibility of these injuries happening to your employees. Choosing protective eyewear can be a daunting task with many options to choose from and many factors to consider. The primary factor is knowing which tasks your employees will perform that require safety eyewear; this will drive the other choices that you will make.
Lens
The quality of the lens will determine how effective the eye protection will be, so this is probably one of the most important choices you will need to make.
In 2003, the American National Standards Institute revised their impact levels. There are now two levels of acceptable impact resistance—high and basic. Basic impact lenses must pass a “drop ball” test. This involves dropping a one inch in diameter steel ball onto the lens from a height of 50 inches. Lenses that pass the basic impact test are marked “Z87.”
High impact lenses resist shattering when quarter-inch steel balls are shot at different speeds at the lens. Glasses will resist shattering when the steel balls are shot at 150 feet per second. Goggles are able to resist at up to 250 feet per second, and face shields resist at 350 feet per second. High impact lenses are marked “Z87+.”
Frames
With the ANSI revisions, all eyewear and goggle frames, face shields or crowns must also comply with the High Impact requirement. Although your hazard assessment may not indicate the need, High Impact for both frames and lenses would always be recommended.
Lens Materials
Several materials are used to make safety lenses: glass, plastic, Trivex® and polycarbonate. Let’s look at each one.
Glass. Safety eyewear with glass lenses is still manufactured. The main benefits of glass are excellent clarity and superior scratch resistance. However, glass lenses tend to be heavy and will shatter easily. They are used only in special situations where the density of the glass is needed due to chemical usage or the work environment.
Plastic (CR 39) lenses are much more impact resistant than glass. They are also much lighter than glass (about half the weight). This type of lens lends itself to more choices for coating and tinting. Plastic lenses are often used around chemical solvents because they resist breakdown and pitting.
Trivex® is a polymer with many of the properties of polycarbonate—light in weight and resistant to impacts but with superior optical clarity. It is one of the newer materials and may well become the most popular.
Polycarbonate is the most common material used in safety eyewear lenses. It is inexpensive and lightweight—lighter than plastic, glass or Trivex®. But although it is lightweight, polycarbonate is actually more impact resistant than glass, Trivex® or plastic. Another benefit of polycarbonate is that it inherently blocks 99.9 percent of UVA/UVB rays without any extra or special coatings. (It can, however, be coated and tinted.)
Coatings
Like the various materials that can be used to make lenses, materials for coatings are just as varied. Here are some of the available options:
Anti-fog provides excellent fog protection in an environment of high humidity where your employees may experience sudden temperature shifts.
Scratch resistance can extend the life of the lenses by preventing scratches that can occur through regular use.
Anti-static helps to reduce the likelihood of dust and particles sticking to the lenses.
Anti-UV blocks up to 99.9 percent of harmful UV radiation from reaching and damaging the eyes.
Lens Tint
Like the lens material and coatings, lenses can come in many different tints depending on when and where the safety eyewear will be used.
Clear eye protection has no color in the lenses. They are good for general indoor environments with normal to low light where the main need is protection from impact.
Indoor/Outdoor glasses have clear lenses with a slight mirror coating. They can be used both inside and out, they’re described as darker than clear but lighter than gray.
Gray tints are used for outdoor work in sunny environments. This tint allows for good color recognition.
Mirror provides general purpose sunglass protection by reflecting a good amount of the light before it passes through the lenses to the eyes.
Amber is recommended for low light conditions like hazy, overcast days and dawn and dusk.
Brown is similar to gray but allows for better contrast and depth perception.
Filter shades protect against both UV and infrared radiation that is produced in welding, cutting, soldering and brazing. The shades range from 1.5 (the lightest) to 14 (the darkest). The shade is chosen according to the task being performed and the amount of light that is generated.
All of these options can make choosing the best type of safety eyewear a difficult task. The importance to your employees, however, cannot be overstated. The best thing you can do to protect your employees’ eyes and vision is to get them the best protection and ensure that they use the protective eyewear as directed.
Diane Kelly is a safety specialist with Intec, Waverly, Pa. Intec is AWCI’s safety consultant.
