Face and eye injuries occur at an alarming rate and with a tremendous cost. Most employers provide protective spectacles but less than 30% of those covered by OSHA include a faceshield.
PPE protects in different ways. Some products erect a barrier between the wearer and job hazards, others attenuate impact force, others filter the hazards from the air. Faceshields erect a barrier between the wearers face and eyes and the hazards of the job.
To OSHA and in the ANSI Standard, faceshields are considered "secondary protection" with protective spectacles being considerd "primary" protection. That means a worker does not have to always wear a faceshield over spectacles, but he/she always has to wear protective spectacles under a faceshield.
A faceshield consists of 3 components: a crown deflector, a window, and a headgear. The purpose of wearing a faceshield is to erect an effective barrier sufficient to cover as much of the face, eye and crown area as possible. As always, there are vast differences in design, material and quality between brands. There are a number of things to consider and evaluate to determine which are the best faceshields for your operation.
Performance begins with the crown deflector. It should be designed to cover a broad and deep area with multiple depths for various applications. The top quality suppliers offer 3", 5" and 7" deflectors to meet your specific needs without compromise. The crown deflector contains the window mounting system. The latest and best window mounting systems utilize a "Channel Grip/Locking Cam" method for the best possible seal between the crown deflector and the window. More on that follows in the window discussion. Finally, the material the crown deflector is molded from is critical. The top quality brands are molded from NORYL, or another engineering grade thermoplastic. NORYL, the same material the leading brand of welding helmets are molded from, is a strong, chemical and heat resistant material that allows faceshields molded from it to be used across the widest range of applications.
Faceshield windows should also be designed to provide maximum coverage of exposed facial area. They are measured by width (ear-to-ear) and depth (forehead-to-chin). Look for the widest and deepest you can find. They also come in various shapes with most being rectangular but the leading brand (pictured above) providing the widest and deepest with a special angled design to allow freedom of movement of the head.
Even more so than in the crown deflectors, material is a critical factor in faceshield window effectiveness. Most windows are produced from acetate, PETG, or polycarbonate. But the best windows are made from propionate, the best all around material on the market. Each of the other materials has one or two features at which they excel but they also have significant drawbacks. Propionate provides the best performance across the board in the characteristics that are most important in a high performance faceshield window. Polycarbonate should be evaluated very carefully. Yes, it offers the best impact resistance, but most face and eye injuries are not high impact "blow through" type injuries. But Polycarbonate is adversely affected by so many substances (including most lubricants, solvents, hydrocarbons, etc) commonly used in industry and construction that it must be used only when absolutely needed for impact protection.
Most importantly, propionate provides the best optical quality available. Placing a curved window, made from a lesser material, in front of the eyes can create distortion and a number of other visual problems. Propionate provides a chrystal clear, distortion free view for an extra margin of comfort and protection.
Another important evaluation of faceshield windows is how they are made. Most windows are stamped out of flat sheet stock. Therefore, they must be bent into the curved shape of the crown deflector when they are mounted. Forcing the flat windows into shape creates visual distortion and can create stress lines in the window that could cause it to fail on impact. The leading supplier of top quality faceshield windows injection molds them from propionate then forms them to the exact curve of the crown deflectors. Those advanced techniques eliminates any visual distortion and stress on the window. The injection molded, preformed, propionate windows mount easier, stay on better, and provide the best optical quality in the industry.
The brand you chose should provide the maximum range of specialty faceshield windows available. Using propionate as the base material allows the quality leader to provide green tint windows for glare; IR/UV (shades 3, 5 and 8) windows for Oxy-Fuel and Plasma Arc operations; and true color gray for outdoor construction applications. They also provide gold plated windows for high heat applications. The gold plated windows have to use polycarbonate as the base because of the high heat of the liquid gold plating.
In addition to quality components, the way they go together to work together plays a big part in the performance of a faceshield. The way the window mounts and fits on the crown deflector is a critical factor.The illustration above identifies 4 key considerations. Going from top to bottom, the first arrow shows the "Channel Grips" which are strategically placed extensions to help keep the window attached if struck on the bottom. The second arrow identifies the "Mounting Channel" which is a unique recessed channel in the crown deflector for the window to fit firmly in. The third arrow identifies the "Slot pins" which are pins molded in the deflector that fit through slots in the windows eliminating the need for ineffective snaps. And the fourth arrow identifies the "Locking Cams" that lock the window firmly in place in the mounting channel for a perfect seal from dust, dirt and debris. This is the most advanced, most effective method of mounting a window on a faceshield.
Obtaining a perfect seal between the window and the crown eliminates the hazard of dust, dirt and debris from filtering in between the two in gaps, and separations created by snaps and other lesser methods of attachment. Most eye injuries are caused by dust, dirt and debris penetrating the seal between the window and crown. Make sure that you select only the absolute best design for a perfect seal.
Finally, the headgear is the only part of the faceshield that comes in contact with the wearers body. It must hold the faceshield securely in place while at the same time being comfortable enough to not distract or fatigue the wearer. Look for a material that is supple enough to conform to the shape of the wearers head; look for multiple overhead adjustments to align the wearers line of vision; and look for a quality small increment ratchet adjustment that provides just the right degree of individual fit and feel for the wearer.
Now you know what to look for when you consider and evaluate faceshields. If you are providing protective spectacles but you are still experiencing face and eye injuries, add faceshields to the mix. If you do your homework, look at everything available, and evaluate carefully, you will select the best and you will be glad you did.
