Our face is one of the most vulnerable regions of the human body. Anything that does damage to the face can easily damage our eyes, mouth, nose, and other sensitive areas. That said, when working with chemicals or performing potentially hazardous tasks, it is a necessity to strap on a face shield.
Now it’s not just about using A faceshield but using the RIGHT ONE for the job. Having the wrong face shield can aggravate things or worse, even be the cause of the injury itself.
There are multiple options we have to consider when picking a faceshield for a task. Let’s start with the basics, mainly the different the US (ANSI) and European (EN) standards.
Impact resistance:
ANSI or the American National Standards Institute requires each face shield be marked with the manufacturer’s identity and all components pass – and consequently be marked – Z87 or Z87+ (more on this in a bit.) Its resistances and functionality must be on the shield as well.
While the other markings are self-explanatory, Z87 and Z87+ might sound a little alien. Well, let’s shed some light on this. Both standards are listed in the ANSI Z87.1 section and are pretty straightforward.
- Mark Z87 is a basic impact face shield. This means it should be capable of resisting impact from a 1 in. (25.4mm) diameter steel ball dropped from a height of 50 inches.
- Mark Z87+ on the other hand is a high impact face shield that can resist impact from a .25 inch (6.35mm) diameter steel ball traveling at a velocity of 300 feet per second (91.4 m/s).
The European standard (EN 166), on the other hand, requires face shields to withstand impact from a 6mm diameter steel ball at various speeds. Here’s a quick summary of the different classifications.
- Mark A: 190 m/s.
- Mark B: 120 m/s.
- Mark F: 45 m/s.
The second thing we must consider is lens quality. Aside from the fact that bad lenses will cause eye strain, any protective device that prevents the user from seeing clearly will find itself worn incorrectly or even worse, mothballed.
ANSI has some standards regarding lens quality as mentioned in the Z87.1-2010 standard. Under the optical requirements set, the lenses of the protectors must:
- Be free of visible defects
- Have a luminous transmittance level > 85 percent (if the lens is clear)
- Not exhibit >3 percent haze
- Be within acceptable tolerance levels for refractive power, astigmatism, resolving power, prism and prism imbalance
Materials:
Now, let’s look at the different materials available for faceshields. Each one has its own advantages and disadvantages as we will be discussing:
- Polycarbonate (PC) provides good impact and heat resistance. It’s not very chemical resistant, although some PC faceshields provide resistance to chemicals depending on thickness and coatings. UV filter additives can also be added to provide UV protection. These variants often have a “U” in the markings, with U6 being the highest protection available.
- Propionate (PROP) is ideal for protection against chemical splashes. Generally though, most PROP faceshields do not meet impact requirement but there are a few of them out there that are thick enough to make the Z87+ requirements.
- Mesh is another common material used for faceshields and is often used when a lot of ventilation is needed such as in humid areas. Generally, mesh faceshields do not provide impact, chemical, or UV protection.
- Acetate facemasks are often scratch and chemical resistant but often slightly sacrificing visibility. These faceshields generally are not very impact resistant (though there are a few exceptions). Expect these masks to cost more than the average mask since Acetate is pretty expensive.
- PETG offers excellent chemical splash protection. While relatively plentiful, optically correct PETG are hard to come by. This makes it pretty rough on the eyes after some use. Faceshields made from this material generally do not pass impact requirements.
Lens options:
Now that we’ve discussed the base materials there are a variety of lens options:
- Clear lens: Provides the best visibility for both normal and low-light conditions
- Tinted lens: Used for preventing eye strain caused by excessive glare. More details on this can be found in the ANSI/ISEA Z87.1-2010.
- Shade IR: Protects the eyes from IR light, a common feature on masks used for gas soldering, light cutting, brazing, and metal pouring.
- Arc Lens: Protects against low-level arc flashes. These items protect users from electromagnetic energy, tiny fragments, and molten metal released during an electric arc. Be sure to pair this with other PPE equipment to ensure that your workers are completely protected.
- UV Filter: Protects the eyes and face from UV radiation found to cause cataracts, skin cancer and other terrible conditions that we all would like avoid.
Coatings:
- Anti-fog: As the name suggests, it prevents fogging due to water vapor. While there are no ANSI/ISEA tests for it, EN standards have dictated a standardized test which means you might want pick something up that has undergone that test.
- Anti-Scratch: Same for the above, ANSI and ISEA has yet to develop standardized testing for this. The European counterpart, EN, does have a standard in place though so keep this in mind when choosing one.
- Reflective: Mirrored coatings which reflect and dissipate radiant heat. Useful when working in hot environments. Expect to pay a premium when picking up a faceshield with this option.
So many different lenses, so little time!
As you can tell there are a huge number of possible variations on faceshields. While we wish we could say which one is the best one (to make choosing easier for you), it really depends on the environment and circumstance the face shield will be used for. As always, be sure to do your research through articles such as these to make an informed decision as to what faceshield you will be providing your workers. So until the next article, stay safe and keep checking back for more news and info here at the Seton.com Safety Blog.