Frequently Asked Questions
Eye & Face Protection
The optical quality of an arc flash face shield has many variables that need to be considered. A few of the most important terms and definitions are listed below.
Prismatic Power and Imbalance
Prismatic power is defined as any the deviation of a ray of light through a specified point on a lens. Prism in a face shield can be produced when the front surface is not parallel to the back surface. When light passes through the prism, the object viewed appears to be displaced. Any imbalance in these surfaces can cause the wearer to see differing prismatic effects that can cause discomfort for the wearer.
Refractive Power and Astigmatism
Irregularly shaped visors with a lack of optical symmetry can cause light to bend improperly creating astigmatism (i.e., refractive error that causes objects to appear blurry). Refractive power (measured in diopters) is the ability of the lens to focus light properly thus keeping images crisp.
To better understand what an astigmatism is, a cosmetic raytraced image of a lens with target lines crossing the eye centers is listed below. By observing you can see the following.
- Horizontally the image is compressed. This is due to a strong curvature of the face shield. This creates negative horizontal power. The shifting of the image is what we call prism.
- Vertically the image is less compressed. There is very little power and prism. This is due to the lower curvature in this direction.
- The discrepancy between horizontal and vertical power is what causes astigmatism.
I have an older Oberon 40 cal arc flash suit with a green shield. Can I replace the shield with the new TCG faceshield?
I have an older Oberon 40 cal arc flash suit with a green shield. Can I replace the shield with the new TCG faceshield?
It is not possible to replace an older style, green arc flash face shield with the a new True Color Grey (TCG™) face shield due to the hole pattern configuration. Each Oberon face shield has a unique hole configuration which allows it to be affixed to an Oberon hood. Due to this fact a new hood must be purchased if your green shield gets damaged.
How do I clean and disinfect my Oberon face shield?
To clean and disinfect an Oberon face shield it is best to use a damp, soft cloth and gently wipe away any dirt or grit. Once this is done gently flush them off with room temperature tap water.
To disinfect a FaceFit™ shield clean first and then dampen a soft cloth with isopropyl alcohol or use a Lysol® wipe. This process may leave streaks as the surface dries. Once dry, use a soft clean cloth and lightly wipe off any streaks or film left on the shield from impurities in the wipes.
As an alternative method a 2% solution of Clorox bleach (Sodium Hypochlorite or NaOCL) and cool water can be used. Apply the solution by gently spraying the face shield and then allowing it to evaporate. Once dry the shield can be rinsed off with cool tap water.
How do I clean and disinfect safety googles and spectacles?
To clean and disinfect Oberon safety goggles and spectacles it is best to use a damp, soft cloth and gently wipe away any dirt or grit. Once this is done gently flush them off with room temperature tap water.
Once the safety goggles or spectacles are cleaned it is also important to disinfect them. Take a soft cloth that has been dampened with isopropyl alcohol or use a Lysol® wipe and gently clean the inside and out of the goggles. It is also important to wipe the elastic strap on the goggles. This process may leave streaks on the surface of the goggles or spectacles as they dry. Once dry, use a soft clean cloth and lightly wipe off any streaks or film left on the shield from impurities in the wipes.
How do I clean the inside of my arc flash hood?
The first step to cleaning and disinfecting an Oberon TCG™ hood is to disassemble your hood. Once done, if the shield has dirt or grit, flush it off with room temperature tap water.
The next step to disinfecting a TCG™ hood window is to take a soft cloth with isopropyl alcohol or use a Lysol® wipe and gently clean both sides of the shield. This process may leave streaks as the surface dries. Once dry, use a soft clean cloth and lightly wipe off any streaks or film left on the shield from impurities in the wipes.
As an alternative method a 2% solution of Clorox® Bleach (Sodium Hypochlorite or NaOCL) and cool water can be used. Apply the solution by gently spraying the face shield and then allowing it to evaporate. Once dry, the shield can be rinsed off with cool tap water.
To clean and disinfect the fabric portion of a hood first remove the shield and launder the hood per the washing instructions on the hood label. The steps above will help to remove most of the dirt, germs, and possible viruses that could be on the hood after use.
Does the Oberon TCG™ Series shield block Infrared light? I am worried my eyes might be damaged if I am hit with and arc flash.
Does the Oberon TCG™ Series shield block Infrared light?
When you are involved in an arc flash two things occur simultaneously and help prevent damage to your eyes.
- You blink. This happens very quickly. A good example of this at work would be when you accidentally look at the sun. Your first reaction is to immediately close your eyes. The blinding flash of an arc lasts as long as the arc flash is present. This would be about one third of a second for a 12 calorie arc flash and up to 2 seconds for a 100 calories/cm2 arc flash. The human eye response is about 1/10th of a second to blink. Therefore in about 1/10th of a second in all arc flashes the eye blinks to reduce the visible light reaching the eye. While we do not want to overexpose the eye to this visible light there is a natural response and self-limiting mechanism.
- A second protective mechanism occurs in our TCG™ Shields when they are hit with an arc. There are additives in the shields that will carbonize in about 1/10th of a second. This carbonization will reduce all of the electromagnetic spectrum and most of the arc flash visible light. Essentially the front surface looks a lot like asphalt moss once it is hit with an arc flash. Please see the attached picture for reference. The combination of these two things prevents any significant damage to the eyes from occurring.
What are the limitations of an arc flash rated suit?
A common misperception is that a person wearing an arc rated suit is “bullet proof” from the hazards associated with electricity. There are 3 main potential hazards when working with electricity: Electric Shock, Arc Flash and Arc Blast. An arc flash suit can protect you from an arc flash provided that the incident energy level that the suit is exposed to is equal to or less than what the suit is rated for. All arc tested suits will come labeled with an estimated APTV level measured in calories/cm2. Oberon recommends having a risk assessment done before working on any electrical equipment to help identify the possible risks associated with the work task to be performed. Once this analysis is done the appropriate APTV level needed can be determined and the proper PPE selected.
This leaves two other potential electrical hazards that could potentially harm you. The arc blast is high pressure sound wave that is caused by a sudden arc fault. It can cause molten metal droplets to be propelled at high speeds as well as sudden expansion of air pressure that can blast out. An arc flash suit offers some protection from these types hazards, but only in a limited capacity. For instance, if a blast pressure wave were to be strong enough to propel a worker across a room an arc flash suit would not be able to protect the worker from the force of the wave.
The last type of electrical hazard that a worker can be exposed to is electrical shock. Shocks are caused when contact is made by a worker with an electrical energy source. Arc flash suits are not tested or designed to protect workers from this type of hazard. Typically workers will wear rubber electrical gloves with leather protectors when there is a risk of electrical shock while performing their work task.
How do I pre-use inspect my arc flash faceshield?
The NFPA 70E Standard requires that all arc flash PPE is pre-use inspected. Refer to Oberon’s resource section of the website for literature resources including User Guides and Storage, Use, Care & Maintenance files. While inspecting your arc flash faceshield if you identify a problem do not use the product until the issue has been repaired, cleaned or replaced. When pre-use inspecting your Oberon arc flash suit you should inspect each item one at a time.
The following steps apply when pre-use inspecting your Oberon arc flash faceshield;
- Check the faceshield visibility, inspect for excessive scratching. If visibility is impaired or the shield is cracked or damaged remove from use (replace with appropriate lens).
- Manually adjust the shield mounting mechanism (adapters) to ensure wing nuts are firmly in place, do not over tighten or the shield won’t be able to operate correctly.
- Inspect adapters for cracks or damage, ensure fingers are locked into hard hat slots.
- Check hard hat slots and inspect for cracks that could allow the adapter to slip out.
- Ensure the nuts and bolts fastening a lower chin guard (double crown) are tight before use.
How do I activate my Oberon anti-fog coating?
Oberon arc flash faceshields and suit hood shield windows are available with anti-fog coatings. Before each and every use the anti-fog coating must be activated. Workers must use humidity to activate the anti-fog properties by pulling the inside of the faceshield or hood lens towards them and breathe on the surface. It’s important for your shield lens to be at room temperature for best results.
When using an Oberon arc flash suit hood, consider using a hood ventilation system that circulates air to your breathing zone. Oberon’s system delivers the external air directly down the inside of the hood shield window to reduce fogging in extreme conditions.
Can we use the new True Color Grey (TCG) shield in our old Oberon arc flash suit hoods?
No, older Oberon hoods that have a green/yellow shield window lens cannot be exchanged for the new clear TCG shield window. When Oberon designed the hoods for the new TCG shield lens, changes were made to the fabric construction and installation method. The new TCG shield lenses have metal snaps that make assembly and disassembly easier for the worker. All older Oberon hoods must be replaced with complete TCG hoods when upgrading to the new technology.
The ASTM F2178 Standard requires the hood to be tested as you would use it. This final product testing requirement is critical for the product to perform as needed during an arc flash exposure.
What is the difference between green versus grey arc flash faceshield or hood lenses?
Both Oberon green/yellow and new clear True Color Grey (TCG) lenses provide protection from an arc flash incident. A clear grey lens is safer than the old green technology because the likelihood of a worker making a mistake that could cause an arc flash has been reduced.
Oberon’s True Colour Grey is a medium density filter that allows all visible light to pass through it with no distortion. Oberon TCG is a nearly clear lens that provides the same protection as old style green with the difference being workers can finally see the true colours of their work.
Can I use Febreze on my PPE?
The stock answer is “the garments should be free of flammable contaminants”…whether that be oily/flammable dirt or additives from the cleaning process such as fabric softeners. The MSDS for Febreze states that Febreze does contain Ethanol which is flammable (also documented in the MSDS). If you require a blanket statement that it is OK to use Febreze regardless of how or how much is used, then the answer is NO because the MSDS states clearly that there is a flammable component in the solution.
Which safety spectacles are suitable to wear with arc flash face shields and hoods?
There are some companies in the market that promote “arc flash protective safety spectacles”. Even if the spectacles were manufactured with a material that absorbed the thermal energy of an Arc Flash incident (like Oberon’s arc flash face shields and hood windows) the limited surface area of the user’s face that a spectacle would cover would make the product ineffective at best! Much of the users face would be severely injured/burned by the thermal energy of the arc flash. Further, there would be limited protection to the face against injury from shrapnel created by the arc by a simple spectacle. It is important to note that the standards do not recognize the use of safety spectacles or “arc flash” goggles as suitable/ recognized arc flash protection.
NFPA 70E references the use of ANSI Z87.1 safety spectacles under a face shield or hood because the ANSI Z87.1 Standard (Practice for Occupational and Educational Eye & Face Protection) obligates the user to wear a safety spectacle or safety goggles under a face shield or hood window. Ultimately, a face shield is considered to be a secondary eye protective devise even though it covers your eyes and your face you still need to wear a primary eye protective device under the face shield such as a safety spectacle or cover goggle. Many users may be tempted to wear a face shield without safety spectacles beneath because it may not seem to make sense, but that is in the standard and that is what OSHA is looking for. NFPA 70E is not referencing any specific safety spectacle, nor one with any enhanced thermal protection. It is only calling for a safety spectacle (a simple clear lens safety spectacle such as Oberon T788-30).
It is important to note that one should be cautioned against wearing metal framed spectacles, either safety or prescription. If the spectacles were to fall from your face, into an energized system, the metal could initiate the arcing fault, which could cause an arc flash.
If the user or his employer have conducted an incident energy analysis and determined the level of suitable arc flash protection for the task to be performed, the standard is not calling for the use of a safety spectacle with enhanced protection. They simply want a safety spectacle per ANSI Z87.1. The face shield or hood window is providing the protection against the thermal incident energy.
Legal:Always conduct a task based risk assessment procedure to determine the proper PPE. The statements made here are for informational purposes only. This and Oberon’s marketing material does not recommend specific solutions for specific tasks but provides recommendations based upon its customer’s input. This and Oberon’s marketing material are in no way a substitution for the actual safety standards referenced or implied. Please refer to the actual standards or consult your supervisor, safety officer or human resources with any questions you have regarding the standards or the proper personal protective equipment (PPE) for your task.
Can I use anti-fog wipes on Oberon products?
It is not recommended to use wipes on most of our arc flash face shields and arc flash hood windows as they already have a permanent anti-fog coating on the inner surface. Using wipes will likely damage the coating causing it to stop working. If the coating has been damaged already and does not function, we would then suggest that you experiment with the wipes in a bottom corner of the face shield to insure that it does not have any adverse results. The use of anti-fog wipes (that we are aware of which are primarily alcohol in nature with a small amount of anti-fog surfactant) will not cause the face shield to weaken or crack. The only adverse reaction would be to damage the coating or surface causing it to haze, making visibility difficult. There are Oberon arc flash face shields and safety face shields that do not have the permanent anti-fog coating on the inner surface. The use of anti-fog wipes with a small amount of caution (experimenting as above) should be okay to use with these.
Do I need to wear safety spectacles under your face shield?
Yes, applicable Standards including NFPA 70E require safety glasses/spectacles to be worn as primary eye protection. An arc-rated face shield or suit hood is designed to protect your face. Both safety glasses and arc-rated protection is required when an arc flash incident is likely to occur.
The ANSI Z87.1 standard covers industrial eye and face protective devices and their use in the marketplace. It defines safety glasses and safety/cover goggles as primary eye protective devises. Their job is to protect your eyes! A face shield is defined as a secondary protective device, requiring the use of a primary protective device underneath. The standard envisions the face shield protecting the face, even though your eyes are a part of your face.
What determines which eyewear to choose?
The NFPA 70E Standard identified safety glasses or safety goggles as selection required “SR”. The risk assessment includes hazard identification. The potential hazards then determine what type of primary eye protection is necessary.
Also consider the comfort of the worker. If the spectacles/goggles are not comfortable they won’t be worn properly. The style is important because everyone wants to look their best and wearing safety eyeglasses are no exception. Size, if the eyeglasses don’t fit properly then they won’t protect properly.
What color lens should I choose?
Clear- works well in indoor and outdoor applications provides excellent light transmission.
Amber- works well in low light work areas, works well in high glare areas and where a contrast is needed.
Dark Grey- works well for outdoor where sunlight and/or glare can cause problems. Dark Grey lens allows wearer to see colors more clearly.
I have a pair of really cool sunglasses that I purchased from Wal-Mart can I wear those?
It depends if they have the ANSI Z87.1-2010 stamped on their frame along with the Manufacturer’s logo stamped on the lens. Only this certifies that the spectacle in question have passed the ANSI standards for Safety Glasses. If they don’t meet those standards you could be putting yourself and your eyesight in danger!
How come I feel dizzy and get a headache when I put my safety glasses on?
Safety glass manufacturers have to adhere to very tough standards for the optical clarity and manufacture. Many times if you are not used to wearing eyewear you will find some discomfort wearing glasses for the first time and it may take a day to get used to them.
Do I have to wear safety glasses under my goggles or face shield?
Yes, OSHA requires the individual to wear safety glasses under goggles, face shields and welding helmets because the individual may lift the goggle, face shield or welding helmet and be exposed without the safety glasses.
Is eye injury common in the American workplace?
Yes, there are estimated 1,000 eye injuries occurring every day. Medical expenses, lost time, lost production, workmen’s compensation adds up to $300 million. This doesn’t include the price of adding up the price that the individual worker pays personally.
What do I have to know about wearing a face shield properly?
Assess the hazard, choose the window material is it a chemical splash, will the splash damage the window making it difficult to see. Polycarbonate offers excellent visual clarity, coated windows offer additional protection for splash, scratch resistance, heat, radiant energy and UV applications where UV is used to dry or sterilize products. If using a headgear make sure you adjust not only the size adjustment but the top adjustment that helps to place the shield at the right height. Make sure the window is properly secured so it doesn’t come off at a bad time.