Safety Eyewear Without Fogging
Don’t let smoke into your eyes or foreign objects.
Smoke can take considerable time to dissipate after fires.
Frame and lens materials have better heat resistance and antifogging properties than others. Fire grade positive seals of protective eyewear in cases of recent Tathra fires would have been ideal in reducing eye inflammation from smoke as would correct masks and respirators.
Should safety eyewear fog up under hot or steamy conditions, and if removed increased exposure to a possible variety of hazards could ensue.
Sixty per cent of all eye injuries happen in the workplace ,so every workplace, regardless of industry, should have eye safety procedures. Many people need education in this regard.
Radiation damage and the eye
- UVC 100 – 280nm. Blocked by the earth’s atmosphere. No ocular absorption.
- UVB 280 – 315nm. Absorbed into the cornea. UVB can directly damage skin cells’ DNA and are the main rays that cause sunburn. They are thought to cause most skin cancers .Basal cell carcinoma (BCC) is the most common cancer in the world. Eighty per cent of BCCs occur in the head and neck region, of which 20 per cent occur on the eyelids,
- UVA 315 – 380nm. Transmitted into the ocular media. The longer the wavelength, the deeper the penetration. These rays are linked to long-term skin damage such as wrinkles, but they are also thought to play a role in some skin cancers.
Gamma rays, X-rays, and high ultraviolet radiation can be a health hazard as it penetrates the body and will transmit through spectacle glasses though it will appear denser than soft tissues. This ionising radiation can cause cell damage ( from spectroscopy studies) as opposed to the nonionising radiation of visible light wavelengths and lower .
The longer wavelength and lower energy microwaves and radio waves will penetrate the body with some absorption. The eyes are one of the most sensitive organs in the body for microwaves. The microwaves excite the water molecules in the body and cause heat damage effects at high levels.
Special shielding similar to faraday cages is required to block this kind of radiation, glasses do not prevent transmission
All standards for electromagnetic radiation transmitting equipment, including those emitting microwave radiation, set safe limits, which are much below what will cause damage to the body.
Though the sun emits all of the different kinds of electromagnetic radiation, 99% of its rays are in the form of visible light, ultraviolet rays, and infrared rays (also known as heat).
Type of Hazard
High speed particle
Impact resistant lens (Polycarbonate); Lens coverage / size; side shields; Impact resistant frame or face shield; Lens stability and bevel profile.
Impact resistant lens; Lens coverage; impact resistant frame or protective google; Lens stability.
Sealed goggle, ventilation and fogging; Scratch resistant protection front and back lens surface.
Radiation (including UV) & Heat
Non-conducting frame; radiation protection and face shield; visible light control (welding); lens stability in frame; coating stability.
Chemical or biological spatter
Sealed goggle, ventilation and fogging; Ease of decontamination
AUSTRALIAN STANDARDS EYE PROTECTION
Eye injuries in the workplace are most commonly caused by grinding and welding, usually in the fishing, construction, manufacturing, agriculture, forestry and mining industries .
Not wearing eye protection such as uvex overspecs,full vision googles or faceshields,or prescription safety glasses can lead to eye injury.
The best assurance is the use of the Standards Mark. Our suppliers are certified to use the Standards Mark.
Whilst Solar UVC is absorbed by the atmosphere, artificial sources of UVC may still be present.
Depending on the properties of the material different wavelengths of UV and visible radiation will either transmit through the lens or be blocked or reflected. This is the case for UVC, UVB and UVA. Not all contact lenses will block UV transmission, just as not all prescription lenses block UV.
Ocular absorption depends on the wavelengths and the age of the eye.
Sunglasses sold in Australia are not permitted to transmit UVB greater the 0.05% of total transmission, and, no more than 0.5% of total transmission of UVA, even less if the glasses are a category 4 sunglass. Because sunglasses are designed to protect against the sun and there is no UVC at ground level, UVC is not required to be tested. Occupational lenses need to be tested The Australian/New Zealand Standard AS/NZS 1338.1:2012 Filters for eye protectors – Filters for protection against radiation generated in welding and allied operations and AS/NZS 1338.2:2012 Filters for eye protectors – Filters for protection against ultraviolet radiation regulates eye protection in the workplace for occupations both indoors and outdoors where artificial UV radiation may reach potentially hazardous levels.
Safety glasses allow air around the eye area as opposed to a seal against the face, to avoid dust and splashes.
Face shields provide further protection and can also be worn over the safety eyewear
AS/NZS 1336: Recommended practices in occupational eye protection
Section 4 deals with the use of personal eye protectors in industrial settings and gives examples of specific hazards together with recommended eye protection.
Section 7 deals with prescription eye protectors.
AS/NZS 1337: Occupational eye and face protection
This Standard sets down the requirements for non-prescription eye protection.
There are four critical elements in compliant prescription eyewear.
1.) Appropriate frame
2.) Appropriate lens material and thickness
3.) Appropriate fitting
4.) Labelling and assuring compliance
Stop the fog on your glasses and protect your eyes
The interior water vapor condenses onto a single lens because the lens is colder than the vapor, although anti-fog agents can be used.
Antifogging eywear generally have two layers of airtight lenses (innner lens warmer outer lens colder) to prevent the interior from becoming “foggy” by keeping the temperature of the inner lens close to that of the interior water vapour
Ventilation safety glasses can prevent sweat from building up inside.
Fogging is the number one vision-related barrier to wearing safety eyewear.
SAI global certified anti-fog coatings are now available.
Handy belt cases can have them at the ready,so you not caught out.
Clip-ons Attached to a prescription spectacle or plano-lens frame,normally when glare is the only risk.
Overglasses Need to have correct fit/instability.
Wide vision Safety glasses – often resembling sunglasses. Additions such as frame collars provide peripheral protection.
Inserts – Eye protectors with a prescription carrier.
Wide vision goggles – Flexible frame or rigid with a separate cushioned fitting surface and headband.
Welding goggles – added protective measures for welding with air vents and anti-fog coatings.
Face shields can provide additional protection against extreme temperatures to the face, blasts and high impact
Smoke being a mixture of chemicals in gaseous, liquid and solid forms contains different-sized smoke particles .
Smoking tobacco is detrimental as is smoke in your eyes.
Generally eye irritation from smoke can be relieved by flushing with artificial tears and the use of a cold compresses depending upon the circumstances.
Prescription safety eyewear allows
• Increased comfort,improved vision
• Reduced weight.more fashionable
• Less reflection, Less restriction on movement and visual field
COVOID-19 AND SAFETY SPECTACLES
According to the American Academy Of Ophthalmology, COVOID-19 infection also can occur through virus particles entering the eyes. However, there are ways we can help reduce this from happening by protecting yourselves with wrap personal protective eyewear.
More and more people are taking extra precautions, opting to wear Safety Eyewear & Sunwear for everyday protection, and also to help reduce the spread of COVID-19 via contact with the eyes.
Although their appearance is often similar, respirators are designed and engineered for distinctly different functions than surgical masks. The amount of exposure reduction offered by respirators and surgical masks differs. The National Institute for Occupational Safety and Health (NIOSH) and the Centers for Disease Control and Prevention (CDC) recommend the use of a NIOSH-certified N95 or better respirator for the protection of healthcare workers.
The most frequently used respirator in healthcare settings is the N95 filtering facepiece respirator (FFR).
Evolution of Respiratory Protection against Particulate Exposures
Early surgical masks were constructed from layers of cotton gauze.
A surgical mask is a loose-fitting, disposable device that prevents the release of potential contaminants from the user into their immediate environment. In the U.S., surgical masks are cleared for marketing by the U.S. Food and Drug Administration (FDA). They may be labeled as surgical, laser, isolation, dental, or medical procedure masks. They may come with or without a face shield.
Modern respirator maks derived from the need to protect miners from hazardous dusts and gases, soldiers from chemical warfare agents, and firefighters from smoke and carbon monoxide.
The filter mask must be able to capture the full range of hazardous particles, typically within a wide range of sizes (<1 to >100 µm) over a range of airflow (approximately 10 to 100 L/min). Second, leakage must be prevented at the boundary of the facepiece and the face.
The filters used in modern surgical masks and respirators are considered “fibrous” in nature—constructed from flat, nonwoven mats of fine fibers. Fiber diameter, porosity (the ratio of open space to fibers) and filter thickness all play a role in how well a filter collects particles.
In all fibrous filters, three “mechanical” collection mechanisms operate to capture particles: inertial impaction, interception, and diffusion. Inertial impaction and interception are the mechanisms responsible for collecting larger particles, while diffusion is the mechanism responsible for collecting smaller particles. In some fibrous filters constructed from charged fibers, an additional mechanism of electrostatic attraction also operates. This mechanism aids in the collection of both larger and smaller particle sizes. This latter mechanism is very important to filtering facepiece respirator filters that meet the stringent NIOSH filter efficiency and breathing resistance requirements because it enhances particle collection without increasing breathing resistance.
How do filters collect particles?
These capture, or filtration, mechanisms are described as follows:
Inertial impaction: With this mechanism, particles having too much inertia due to size or mass cannot follow the airstream as it is diverted around a filter fiber. This mechanism is responsible for collecting larger particles.
Interception: As particles pass close to a filter fiber, they may be intercepted by the fiber. Again, this mechanism is responsible for collecting larger particles.
Diffusion: Small particles are constantly bombarded by air molecules, which causes them to deviate from the airstream and come into contact with a filter fiber. This mechanism is responsible for collecting smaller particles.
Electrostatic attraction: Oppositely charged particles are attracted to a charged fiber. This collection mechanism does not favor a certain particle size.
In all cases, once a particle comes in contact with a filter fiber, it is removed from the airstream and strongly held by molecular attractive forces. It is very difficult for such particles to be removed once they are collected. There is a particle size at which none of the “mechanical” collection mechanisms (interception, impaction, or diffusion) is particularly effective. This “most penetrating particle size” (MPPS) marks the best point at which to measure filter performance. If the filter demonstrates a high level of performance at the MPPS, then particles both smaller AND larger will be collected with even higher performance.
Filters do NOT act as sieves. One of the best tests of a filter’s performance involves measuring particle collection at its most penetrating particle size, which ensures better performance for larger and smaller particles. Further, the filter’s collection efficiency is a function of the size of the particles, and is not dependent on whether they are bioaerosols or inert particles.
Respirator filters must meet stringent certification tests on “worst case” parameters, including:
A sodium chloride (for N-series filters) or a dioctyl phthalate oil (for R- and P-series filters) test aerosol with a mass median aerodynamic diameter particle of about 0.3 µm, which is in the MPPS-range for most filters
Airflow rate of 85 L/min, which represents a moderately-high work rate
Conditioning at 85% relative humidity and 38°C for 24 hours prior to testing
An initial breathing resistance (resistance to airflow) not exceeding 35 mm water column* height pressure and initial exhalation resistance not exceeding 25 mm water column height pressure
A charge-neutralized aerosol
Aerosol loading conducted to a minimum of 200 mg, which represents a very high workplace exposure
The filter efficiency cannot fall below the certification class level at any time during the NIOSH certification tests
* Millimeters (mm) of water column is a unit for pressure measurement of small pressure differences. It is defined as the pressure exerted by a column of water of 1 millimeter in height at defined conditions, for example 39°F (4°C) at standard gravity.
As a result of these stringent performance parameters, fiber diameters, porosity, and filter thicknesses of all particulate filters used in NIOSH-certified respirators, including N95s, are designed and engineered to provide very high levels of particle collection efficiencies at their MPPS.
Manufacturers of surgical masks, on the other hand, must demonstrate that their product is at least as good as a mask already on the market to obtain “clearance” for marketing. Manufacturers may choose from filter tests using a biological organism aerosol at an airflow of 28 L/min (bacterial filtration efficiency) or an aerosol of 0.1 µm latex spheres and a velocity ranging from 0.5 to 25 cm/sec (particulate filtration efficiency). It is important to note that the Food and Drug Administration specifies that the latex sphere aerosol must not be charge-neutralized.
The generation of the test aerosol can impart a charge on a higher percentage of the aerosolized particles than may normally be expected in workplace exposures. A charge-neutralized test aerosol, like those used in the NIOSH tests, has the charges on the aerosolized particles reduced to an equilibrium condition. Therefore, higher filter efficiency values than would be expected with the use of charge-neutralized aerosols may result due to the collection of charged particles by the filters’ electrostatic attraction properties. Additionally, allowing the manufacturer to select from a range of air velocity means that the test results can be easily manipulated. In general, particles are collected with higher efficiency at lower velocity through a filter.
Both of these aspects yield a test that is not necessarily “worst case” for a surgical mask filter. Because the performance parameters for surgical masks are less stringent than those required for filters used in NIOSH-certified respirators, the fiber diameters, porosity, and filter thicknesses found in surgical masks are designed with significantly lower levels of particle collection efficiencies at their MPPS.
How do surgical mask and respirator filters perform?
Respirator filters that collect at least 95% of the challenge aerosol are given a 95 rating. Those that collect at least 99% receive a “99” rating. And those that collect at least 99.97% (essentially 100%) receive a “100” rating. Respirator filters are rated as N, R, or P for their level of protection against oil aerosols. This rating is important in industry because some industrial oils can remove electrostatic charges from the filter media, thereby degrading (reducing) the filter efficiency performance. Respirators are rated “N” if they are not resistant to oil, “R” if somewhat resistant to oil, and “P” if strongly resistant (oil proof). Thus, there are nine types of particulate respirator filters:
N95, N-99, and N-100
R-95, R-99, and R-100
P-95, P-99, and P-100
Respirator filters are tested by NIOSH at the time of application and periodically afterward to ensure that they continue to meet the certification test criteria. The FDA does not perform an independent evaluation of surgical mask filter performance, nor does it publish manufacturers’ test results. In many cases it is difficult to find information about the filter test results for FDA-cleared surgical masks. The class of FDA-cleared surgical masks known as Surgical N95 Respirators is the one clear exception to this uncertainty of filter performance. This is the only type of surgical mask that includes evaluation to the stringent NIOSH standards. All members of this class of surgical masks have been approved by NIOSH as N95 respirators prior to their clearance by the FDA as surgical masks. The FDA, in part, accepts the NIOSH filter efficiency and breathing resistance test results as exceeding the usual surgical mask requirements.
In studies comparing the performance of surgical mask filters using a standardized airflow, filter performance has been shown to be highly variable. Collection efficiency of surgical mask filters can range from less than 10% to nearly 90% for different manufacturers’ masks when measured using the test parameters for NIOSH certification. Published results on the FDA-required tests (if available) are not predictive of their performance in these studies.
It is important to keep in mind that overall performance of any facepiece for particulate filtering depends, first, on good filter performance. A facepiece or mask that fits well to the face but has a poor filter will not be able to provide a high level of protection.
Respirator and Surgical Mask Fit
Because respirator filters must meet stringent certification requirements, they will always demonstrate a very high level of collection efficiency for the broad range of aerosols encountered in workplaces. There has been some recent concern that respirator filters will not collect nano-sized particles, but research has demonstrated that such particles are collected with efficiencies that meet NIOSH standards. This is not surprising, because NIOSH tests employ small, charge-neutralized, relatively monodisperse aerosol particles and a high airflow.
Thus, the most important aspect of a NIOSH-certified respirator’s performance will be how well it fits to the face and minimizes the degree of leakage around the facepiece. This must be measured for each individual and their selected respirator. Selecting the right respirator for a particular workplace exposure depends largely on selecting the right level of protection.
Respirator fit depends on two important design characteristics:
Whether the respirator operates in a “negative pressure” or “positive pressure” mode
The type of facepiece and degree of coverage on the face
Respirators that operate in a “negative pressure” mode require the wearer to draw air through an air-cleaning device (filter or chemical cartridge) into the facepiece, which creates a pressure inside the respirator that is negative in comparison to that outside the facepiece. A “positive pressure” respirator, on the other hand, pushes clean air into the facepiece through the use of a fan or compressor, creating a positive pressure inside the facepiece when compared to the outside. Negative pressure respirators inherently offer less protection than positive pressure respirators, because inward leakage occurs more easily in the former.
Respirators are classified by the type of hazard they protect against.
Negative-pressure respirators rely on the wearer to pull air in through cartridges or filter.
Disposable respirators, also known as filtering facepieces, are used to help protect against some particulate hazards. They’re lightweight and require no maintenance since they’re discarded after use.
Reusable respirators can be used with particulate filters, gas and vapor cartridges or combination cartridges, which may need to be replaced on a schedule or as needed.
Half-face respirators cover the lower half of the face, including the nose and mouth.
Full-face respirators cover the eyes and much of the face, and can sometimes replace the need for safety glasses.
Positive-pressure respirators do the work of pushing air to the respirator headtop or facepiece; they can either be powered-air, using a battery-powered blower to pull air through a filter, or supplied-air, bringing clean air through a hose from a source outside of the contaminated work area
Tight-fitting respirators must be fit-tested when use is required
Loose-fitting respirators typically have a hood or helmet.
Self-contained breathing apparatus (SCBA) is classified as a positive pressure supplied air respirator, but is different from all other respiratory equipment in that the user carries the source of the clean air with them in a tank.
Cartridges and/or Filters
Per AS/NZS 1715 there are 3 different classes of particulate filters, P1, P2 and P3.
The negative pressure particulate categories are based facepiece coverage. All particulate filtering facepieces that cover the nose and mouth area only can achieve only a P1 or P2 classification. A P3 classification can ONLY be achieved when worn with a full facepiece.
Class P1 particulate filters are used against mechanically generated particulates e.g. silica and wood dust.
Class P2 particulate filters are used for protection against mechanically and thermally generated particulates or both e.g. metal fumes.
Class P3 particulate filters are used for protection against highly toxic or highly irritant particulates e.g. beryllium (when worn with a full facepiece).
Certain contaminants may have specific respiratory selection criteria outside this guide e.g. asbestos.
Gas and vapour cartridges categories are distinguished by their filter type and class.
Filter type A = Certain organic vapours (boiling point above 65⁰C) from solvents such as those in paints and thinners (cartridge label colour = brown)
Filter type B = Acid gases such as chlorine, hydrogen sulfide (sulphide) and sulfur dioxide (cartridge label colour = grey)
Filter type E = Vapours from sulfur dioxide (cartridge colour = yellow)
Filter type ABE = are suitable for both certain organic vapours/acid gases and sulfur dioxide e.g. solvents, chlorine and sulfur dioxide (cartridge label colour = brown, grey and yellow)
Filter type K = ammonia gas (cartridge label colour = green)
Filter type ABEK = are suitable for both certain organic vapours/acid gases, sulfur dioxide and ammonia (cartridge label colour = brown, grey, yellow and green)
(AS) 4381: 2015 SINGLE USE FACE MASKS
Requires Instructions For Use, “The masks should be packed such that each mask can be removed without becoming entangled in another”
|CHARACTERISTICS||LEVEL 1||LEVEL 2||LEVEL 3||TEST METHOD|
Level 1 barrier medical face mask materials are evaluated for resistance to penetration by synthetic blood at the minimum velocity specified, bacterial filtration efficiency and differential pressure. APPLICATIONS: For general purpose medical procedures, where the wearer is not at risk of blood or bodily fluid splash or to protect staff and/or the patient from droplet exposure to microorganisms (e.g. patient with upper respiratory tract infection visits GP)
|Level 2 barrier medical face mask materials are evaluated for resistance to penetration by synthetic blood at the middle velocity specified , bacterial filtration efficiency and differential pressure. APPLICATIONS: For use in emergency departments, dentistry, changing dressings on small or healing wounds where minimal blood droplet exposure may possibly occur (e.g. endoscopy procedure)||Level 3 barrier medical face mask materials are evaluated for resistance to penetration by synthetic blood at the maximum velocity specified, bacterial filtration efficiency and differential pressure. APPLICATIONS: For all surgical procedures, major trauma first aid or in any area where the health care worker is at risk of blood or bodily fluid splash (e.g. orthopaedic, cardiovascular procedures)|
|Bacterial Filtration Efficiency (BFE) %||≥ 95%||≥ 98%||≥ 98%||ASTM F2101-14 or EN 14683:2014|
|Perticulate Filtration Efficiency (PFE) % (0.1 μm)||Not Required||Not Required||Not Required||N/A|
|Differential Pressure (Delta P) mm H2O/cm2||< 4.0||< 5.0||< 5.0||EN 14683:2014|
|Resistance to penetration by synthetic blood (fluid resistance) min pressure in mm Hg for pass result||80mm Hg||120mm Hg||160mm Hg||ASTM F1862 / F1862M-13 or ISO 22609|
Other goggle types and uses
Blowtorch goggles are not the correct filters for arc welding which requires radiation proteection
Sports protection to prevent eye injury eg racketball sports
Astronomy and meteorology uses: dark adaption before going outside at night, in order to help the eyes adapt to the dark.